By Christopher Monckton of Brenchley
As Anthony and others have pointed out, even the New York Times has at last been constrained to admit what Dr. Pachauri of the IPCC was constrained to admit some months ago. There has been no global warming statistically distinguishable from zero for getting on for two decades.
The NYT says the absence of warming arises because skeptics cherry-pick 1998, the year of the Great el Niño, as their starting point. However, as Anthony explained yesterday, the stasis goes back farther than that. He says we shall soon be approaching Dr. Ben Santer’s 17-year test: if there is no warming for 17 years, the models are wrong.
Usefully, the latest version of the Hadley Centre/Climatic Research Unit monthly global mean surface temperature anomaly series provides not only the anomalies themselves but also the 2 σ uncertainties.
Superimposing the temperature curve and its least-squares linear-regression trend on the statistical insignificance region bounded by the means of the trends on these published uncertainties since January 1996 demonstrates that there has been no statistically-significant warming in 17 years 4 months:
On Dr. Santer’s 17-year test, then, the models may have failed. A rethink is needed.
The fact that an apparent warming rate equivalent to almost 0.9 Cº is statistically insignificant may seem surprising at first sight, but there are two reasons for it. First, the published uncertainties are substantial: approximately 0.15 Cº either side of the central estimate.
Secondly, one weakness of linear regression is that it is unduly influenced by outliers. Visibly, the Great el Niño of 1998 is one such outlier.
If 1998 were the only outlier, and particularly if it were the largest, going back to 1996 would be much the same as cherry-picking 1998 itself as the start date.
However, the magnitude of the 1998 positive outlier is countervailed by that of the 1996/7 la Niña. Also, there is a still more substantial positive outlier in the shape of the 2007 el Niño, against which the la Niña of 2008 countervails.
In passing, note that the cooling from January 2007 to January 2008 is the fastest January-to-January cooling in the HadCRUT4 record going back to 1850.
Bearing these considerations in mind, going back to January 1996 is a fair test for statistical significance. And, as the graph shows, there has been no warming that we can statistically distinguish from zero throughout that period, for even the rightmost endpoint of the regression trend-line falls (albeit barely) within the region of statistical insignificance.
Be that as it may, one should beware of focusing the debate solely on how many years and months have passed without significant global warming. Another strong el Niño could – at least temporarily – bring the long period without warming to an end. If so, the cry-babies will screech that catastrophic global warming has resumed, the models were right all along, etc., etc.
It is better to focus on the ever-widening discrepancy between predicted and observed warming rates. The IPCC’s forthcoming Fifth Assessment Report backcasts the interval of 34 models’ global warming projections to 2005, since when the world should have been warming at a rate equivalent to 2.33 Cº/century. Instead, it has been cooling at a rate equivalent to a statistically-insignificant 0.87 Cº/century:
The variance between prediction and observation over the 100 months from January 2005 to April 2013 is thus equivalent to 3.2 Cº/century.
The correlation coefficient is low, the period of record is short, and I have not yet obtained the monthly projected-anomaly data from the modelers to allow a proper p-value comparison.
Yet it is becoming difficult to suggest with a straight face that the models’ projections are healthily on track.
From now on, I propose to publish a monthly index of the variance between the IPCC’s predicted global warming and the thermometers’ measurements. That variance may well inexorably widen over time.
In any event, the index will limit the scope for false claims that the world continues to warm at an unprecedented and dangerous rate.
UPDATE: Lucia’s Blackboard has a detailed essay analyzing the recent trend, written by SteveF, using an improved index for accounting for ENSO, volcanic aerosols, and solar cycles. He concludes the best estimate rate of warming from 1997 to 2012 is less than 1/3 the rate of warming from 1979 to 1996. Also, the original version of this story incorrectly referred to the Washington Post, when it was actually the New York Times article by Justin Gillis. That reference has been corrected.- Anthony
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Greg Mansion says:
June 14, 2013 at 6:10 pm
Therefore your “no warming for X years” argument misses the point and is absolutely worthless.
The latest we have from NOAA on this topic is:
”The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
Did we all miss an update on this topic by NOAA? If so, please enlighten us.
In all of this talk about averaging models, etc, and selecting the best ones and discarding the worst, it brings to mind the graphs we see every year (and especially those of us in Florida pay very close attention to). I refer, of course, to the projected hurricane tracks from the various models which are out there. I’m sure the models are quite complex, and they do their bestto predict the hurricanes’ paths. What we see on the news or the NOAA website is a simple “skinny line” as they call it of the projected track.
Viewing a spaghetti plot of the different models is quite enlightening (as I’m sure most here have done). Sometimes, when the steering forces are very strong they converge on nearly the same solution (in the short term, anyway) but longer term — or in the absence of such forces — they diverge amazingly. I recall seeing the plots of TS Andrea a few weeks ago while it was still forming in the Gulf of Mexico. The model tracks went *everywhere*. Some west, some north, some east….. If the forecasters attempted to average that mess absolutely nothing useful would have come out of it.
I don’t know the history of the models, but I assume some must have been more accurate in certain circumstances (and if they were totally bogus they’d have been tossed), so you have a skilled forecaster looking at all of these tracks, using his experience (and I assume knowing which models did a better job under which circumstances) to come up with a projected track. I recall reading a lot of discussion (in the discussion section of the NOAA site) over the years about how this model or that model wanted to shift the track significantly, but the forecaster didn’t buy it (or only shifted the projected track slightly).
So having the differing models is valuable to give insights to a problem because one model may work better at times than others. But a trained eye needs to make sense of it all. Simple averaging is pointless.
milodonharlani
I gave you a lengthy explaination but the moderators are holding onto it for now.
anyone who says that there has been no warming since the 1998 El Nino needs to realize that this has been one of the warmest years in human history and the last 10 years have been the warmest decade in human history.
unless an annual temperature drops below the 1979 average (which it hasn’t done in over 35 years now) I am not concerned about your pet theories.
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]
Werner Brozek says: June 14, 2013 at 7:13 pm
“Did we all miss an update on this topic by NOAA?”
No. You did leave out that they seem to be talking about ENSO-adjusted trends. But even without that, there hasn’t been 15 years of zero trend. Lord M says that for his 17 year stretch, the trend was 0.89°C/century.
Greg Mansion says:
June 14, 2013 at 7:46 pm
What exactly is your point?
The models have been shown to be wrong by “no warming for X years”.
From the article:
“He says we shall soon be approaching Dr. Ben Santer’s 17-year test: if there is no warming for 17 years, the models are wrong.”
The title said: “No significant warming for 17 years 4 months”
But did you know that RSS has no warming at all for 16 years and 6 months? The slope is actually slightly negative.
Harold Ambler says:
June 13, 2013 at 3:39 am
“1. Time to point out again that when the warmists convinced the world to use anomaly graphs in considering the climate system they more or less won the game. As Essex and McKitrick (and others) point out, temperature, graphed in Kelvins, has been pretty close to flat for the past thousand years or so. The system displays remarkable homeostasis, and almost no lay people are aware of this simple fact.”
The concept of anomaly was adopted so that trends would be the fundamental evidence of climate science. As everyone knows, trends are not evidence. Serious scientists should stop using anomalies.
jai mitchell says:
June 14, 2013 at 7:27 pm
milodonharlani
I gave you a lengthy explaination but the moderators are holding onto it for now.
anyone who says that there has been no warming since the 1998 El Nino needs to realize that this has been one of the warmest years in human history and the last 10 years have been the warmest decade in human history.
unless an annual temperature drops below the 1979 average (which it hasn’t done in over 35 years now) I am not concerned about your pet theories.
—
Actually the 1930’s Dust Bowl years were as warm or warmer, before they were adjusted/homogenized/re-imagined and politically downgraded.
Also, you apparently don’t understand that “warming” and “warm” are two entirely different words.
And recent Antarctic ice core data from the MWP era discredits your notion that the last decade was the warmest in human history.
Bob Tisdale says:
June 13, 2013 at 6:22 am
Another excellent post, Mr. Tisdale. If the Greens could understand you they would champion you as the defender of the natural world against the fantasies of the modelers.
Nick Stokes says:
June 14, 2013 at 8:11 pm
No. You did leave out that they seem to be talking about ENSO-adjusted trends.
We have been through this before and I know you do not agree with me, but for the benefit of new people, the La Ninas immediately following the 1998 El Nino totally cancel the effects of the El Nino.
But even without that, there hasn’t been 15 years of zero trend.
It is zero for over 16 years on three data sets. Here are the exact times and slopes:
HadCRUT3, 16 years, 1 month. slope = -5.84905e-06 per year
Hadsst2, 16 years, 2 months. slope = -0.000360188 per year
RSS, 16 years, 6 months. slope = -0.000286453 per year
To see for yourself, see:
http://www.woodfortrees.org/plot/hadcrut3gl/from:1997.1/plot/hadcrut3gl/from:1997.1/trend/plot/hadsst2gl/from:1997.1/plot/hadsst2gl/from:1997.1/trend/plot/rss/from:1996.9/plot/rss/from:1996.9/trend
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]
Nick Stokes says:
June 14, 2013 at 8:11 pm
Werner Brozek says: June 14, 2013 at 7:13 pm
“Did we all miss an update on this topic by NOAA?”
No. You did leave out that they seem to be talking about ENSO-adjusted trends. But even without that, there hasn’t been 15 years of zero trend. Lord M says that for his 17 year stretch, the trend was 0.89°C/century.
—
And 0.89°C/century = 0.0089C/per year, beyond the precision of the instruments recording the data for the last century, and beyond the uncertainty\error bars of the reported results. Not to mention the fact that the temperature data record has been mangled beyond belief by the gatekeepers.
Thomas says:
June 13, 2013 at 6:56 am
Statistical significance is not a measure but a test. When we say that the number is not statistically significant we mean that our statistical calculations show that the number failed the test and, therefore, has no value.
Jai Mitchell – The last ten years in RECORDED human history (so 200 years divided by 100,000 years equals what per cent?). Every time I travel to the big city and experience that UHI effect, I understand (maybe) where you are coming from. Glad that in the country, we have missed those alleged record setting heat waves.
wbrozek says: June 14, 2013 at 8:47 pm
“I know you do not agree with me, but for the benefit of new people, the La Ninas immediately following the 1998 El Nino totally cancel the effects of the El Nino.”
Yes, I remember some of it but not that. They don’t cancel. Trend is weighted like a seesaw. El Nino at the start strongly downs the trend. Recent La Nina’s push it further down. La Nina immediately following 1998 partly cancels, but has less weight, as well as being smaller.
“Here are the exact times and slopes:”
NOAA specified surface temperature, which rules out two of them. The other is obsolete.
Now online at Forbes. BIG audience. apologies if previously posted in another commentary.
http://www.forbes.com/sites/larrybell/2013/06/09/keep-your-long-flannel-underwear-climate-scientists-predict-hell-to-freeze-over/
Mr. Stokes, having been caught out in a repeated, barefaced lie, continues to wriggle like a stuck pig. He had falsely said, over and over, that Professor Brown had “criticized” one of my graphs, even though Professor Brown had replied to him when he had first made the point. The Professor had explicitly stating that he had criticized the approach taken by the IPCC in the Fifth Assessment Report.
In an increasingly desperate attempt to maintain the lie now that it has been exposed, Mr. Stokes says Professor Brown criticized my graph for the “implicit swindle” of having formed a “mean and standard deviation over model projections and then using the mean as a ‘most likely’ projection and the variance as representative of the range of the error”.
However, I had done no such thing. Nowhere in the head posting, nor in the graphs therein, nor in the previous posting to which Mr. Stokes has already been referred, do I state that I have formed a “mean and standard deviation over model projections”.
Instead, I have simply displayed the range of those projections as it is displayed in Fig. 11.33a of the IPCC’s Fifth Assessment Report, adding the IPCC’s own central projection from the models, which – if Mr. Stokes had bothered to do some reading instead of lying – is given in the following passage from the second-order draft of the report:
“The global mean surface air temperature anomaly for the period 2016–2035 relative to the reference period of 1986–2005, will likely be in the range 0.4–1.0°C (medium confidence) …”. Now, let me see, o.7 ºC is in the middle of that range, and multiplying it by 100/30 to give the centennial equivalent works out at, um, 2.33 Cº/century, which is precisely the value stated on my graph.
AR5 maunders on: “It is consistent with the AR4 Summary for Policymakers statement that ‘For the next few decades a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios’.” And that is equivalent to 2 Cº/century, which is also consistent with the central projection displayed on my graph.
So Professor Brown was indeed criticizing the IPCC, as he had himself explained to Mr. Stokes he was. For the central projection displayed in my graph is the IPCC’s central projection, not mine. I merely reproduced it and correctly attributed it rather than pretending – as Mr. Stokes has unwisely done – that it was mine.
As so often with the paid or unpaid trolls who make it their business to try to divert threads such as this with direct lies, Mr. Stokes mendaciously picks nits from the elephant in the room without appreciating that it is an elephant. The measured global temperature trend since 2005, the year to which the models’ projections relied upon by the IPCC in Fig. 11.33a are backcast, is inconsistent with the entire range of those projections. They go up. It goes down. Up and down are different directions.
===================================================================
Sometimes we can’t see the forest for the trees.
The cause. That’s the point. Is it Man? Those who promote CAGW say it is (“Coal Trains of Death” etc.) and we must mortgage our future for the sake of polar bears. What in their hypothesis of the Man-made cause allows for the absence of the predicted effect?
You’re arguing that the absent effect isn’t absent at all. Why? To keep the Gravy Trains rolling?
When has “climate” never changed?
Mr. Mansion, like many students of logic in their first weeks, is surprised and perplexed that absence of correlation necessarily implies absence of causation. He uses the example of a room heater (which, if on, warms the room) and a window that is intermittently open and shut, varying the temperature so that there is no correlation between the output of the heater and the temperature of the room.
Had he thought for a moment rather than being over-hasty to find fault, he would have appreciated that the variability in room temperature caused by the opening and shutting of the window is not correlated with the steady output of the heater. Nor, of course, is it caused by it. Since the temperature in the room varies and the output of the heater is steady, it should be obvious even to Mr. Mansion that the absence of correlation in his own example necessarily implies absence of causation.
Mr. Mansion also says there is no greenhouse effect. Since the existence of that effect may be deduced theoretically and demonstrated empirically, I beg to differ. Besides, his remark is off topic.
He says global warming is about an overall trend, but neglects to specify the period he has in mind. An elementary textbook of statistics will tell him that a trend without a period is void for uncertainty of meaning. The mean rate of warming in the entire global instrumental record since 1850 is equivalent to less than 0.5 K/century. The maximum supra-decadal rate of global warming since 1850 is equivalent to 1.7 K/century. It occurred from 1860-1880, 1910-1940, and 1976-2001. The IPCC predicts a mean rate of warming of 3 K/century from now to 2100. How likely is that?
Finally, he says my “no warming for x years argument misses the point and is absolutely worthless”. Perhaps he should bother to read the head posting before opening his mouth and inserting his foot. I had made it explicit in that posting not only that the “no warming for 17 years” argument was Dr. Santer’s argument, not mine, but also that [as Dr. Santer, like the NOAA and James Hansen before him, has now discovered] it was imprudent to use such arguments and that it was better to concentrate on the inexorably widening discrepancy between the models’ projected global warming and the far lesser rate of warming that is measured in the real world.
Greg Mansion says:
June 14, 2013 at 8:47 pm
Besides, saying that CO2 is a “greenhouse gas” on the one hand and implying that it does not cause warming on the other is a contradiction.
I see no contradiction at all here. I believe CO2 is a greenhouse gas and that it causes some warming. (Or perhaps I should rephrase that and say it slows down the speed at which the surface of the earth loses heat.) However I believe that the amount of warming it causes is way less than the IPCC estimates and that there are negative feedbacks that reduce the warming due to CO2. I also believe that solar effects and ocean cycles can be a greater influence in the opposite direction to that of CO2.
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]
Monckton of Brenchley says: June 14, 2013 at 9:39 pm
“In an increasingly desperate attempt to maintain the lie now that it has been exposed, Mr. Stokes says Professor Brown criticized my graph for the “implicit swindle” of having formed a “mean and standard deviation over model projections and then using the mean as a ‘most likely’ projection and the variance as representative of the range of the error”.
However, I had done no such thing.”
I don’t endorse RGB’s criticisms. I think they are over the top, and wrong. But it was your graph to which he applied them. He said explicitly that it was, and he referred to no other. True, it seems he thought it was an AR5 graph. AR5 Fig 11.33a has no statistics at all; it’s just a spaghetti plot of model runs and measured temps. And it doesn’t look anything like any of your plots. So he surely can’t have been talking about that.
“Instead, I have simply displayed the range of those projections as it is displayed in Fig. 11.33a of the IPCC’s Fifth Assessment Report, adding the IPCC’s own central projection from the models…”
I don’t particularly disagree with the way you put your graph together. The point is, it is your graph, with your statistical calculations, and that is what RGB criticised.
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]
[snip – Greg House under a new fake name. Verified by network path. Mr. House has been shown the door but decided to come back as a fake persona preaching the Slayer/Principia meme. -Anthony]