Skip to comments.No significant warming for 17 years 4 months
Posted on 06/16/2013 3:08:20 PM PDT by Ernest_at_the_Beach
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 Santers 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. Santers 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 IPCCs 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 IPCCs 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: Lucias 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
All those brainwashed-to-be-scared elementary, jr high and high school kids should know there has been NO warming in their lifetimes.
Oooh, talk statistics to me, Lord Monckton!
Try watching the WEATHER CHANNEL
All you get global warming shoved down your throat
No lomger watch it as cant stomach the propoganda......
Who are you going to believe, the alarmists or your lying eyes?
Sure, it’s a hoax, but Algore gets to keep his millions of dollars, right?
BLIMEY! Something must be DONE ANON!
FREDDY THE WEATHER TOAD SEZ:
KEEP YER BLOODY ANS OFF ME GRANTS
“All you get global warming shoved down your throat
They also throw out the standard lie about ocean levels rising. So the ocean is rising everywhere but the entire coast of North America, South America, Europe, Asia, Africa. Again, exactly where is the ocean level rising?
I have kept record of historical highs for L.A.,CA civic center for a few years here are just a few of them. They have not been broken.
How many jets at airports- how many trucks clogging roadways- what was the population back then?
09/10 103 1878
09/11 101 1878
03/28 90 1879
03/29 99 1879
06/01 100 1879
06/02 104 1879
06/03 99 1879
08/11 98 1879
10/26 95 1879
05/27 97 1880
08/08 100 1881
08/10 99 1882
05/20 99 1883
05/21 100 1883
06/25 98 1883
09/22 104 1883
08/07 99 1884
08/29 102 1884
08/14 97 1885
08/17 104 1885
08/18 102 1885
08/19 106 1885
09/21 108 1885
07/08 95 1886
07/15 98 1886
12/14 85 1886
04/12 97 1888
04/13 99 1888
04/09 94 1890
05/14 96 1890
06/05 98 1890
06/06 102 1890
06/07 105 1890
Lots of pasture back rhen..
Couldn't be that our computer models are wrong. No, it must be RACISM!
I just turned there for a second (all I can stand) and they were blaming how the Mississippi River went from drought in January to flood stage now on the dreaded climate change. Just show me the radar you hacks and leave the propangda to the Goebels in DC.
On your double post....
How do you do that and arrive at the same posting time?
You must have fast fingers....
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