Dr. Roger Pielke Jr. says exactly what I thought: this new paper from Rahmstorf is untrustworthy.
He writes:
Here is another good example why I have come to view parts of the climate science research enterprise with a considerable degree of distrust.
A paper was released yesterday by PNAS, by Stefan Rahmstorf and Dim Coumou, which asserts that the 2010 Russian summer heat wave was, with 80% probability, the result of a background warming trend. But if you take a look at the actual paper you see that they made some arbitrary choices (which are at least unexplained from a scientific standpoint) that bias the results in a particular direction.
Look at the annotated figure above, which originally comes from an EGU poster by Dole et al. (programme here in PDF).
It shows surface temperature anomalies in Russia dating back to 1880. I added in the green line which shows the date from which Rahmsdorf and Coumou decided to begin their analysis — 1911, immediately after an extended warm period and at the start of an extended cool period.
Nyet…more here
Here’s the abstract:
Increase of extreme events in a warming world
+ Author Affiliations
-
Edited by William C. Clark, Harvard University, Cambridge, MA, and approved September 27, 2011 (received for review February 2, 2011)
Abstract
We develop a theoretical approach to quantify the effect of long-term trends on the expected number of extremes in generic time series, using analytical solutions and Monte Carlo simulations. We apply our method to study the effect of warming trends on heat records. We find that the number of record-breaking events increases approximately in proportion to the ratio of warming trend to short-term standard deviation. Short-term variability thus decreases the number of heat extremes, whereas a climatic warming increases it. For extremes exceeding a predefined threshold, the dependence on the warming trend is highly nonlinear. We further find that the sum of warm plus cold extremes increases with any climate change, whether warming or cooling. We estimate that climatic warming has increased the number of new global-mean temperature records expected in the last decade from 0.1 to 2.8. For July temperature in Moscow, we estimate that the local warming trend has increased the number of records expected in the past decade fivefold, which implies an approximate 80% probability that the 2010 July heat record would not have occurred without climate warming.
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Compare that to what NOAA says about it here
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Yeah! This one is not a ” What If Study “. But alas another cherry picked Hockey Stick… 🙁
I realise that graph shown is of temp anomaly but even so, by simple eyeballing, the areas of +ve anomalies is roughly equal to the areas of -ve anomalies. On a simple analysis, would that not suggest that ‘overall’ – there has been no statistical warming in Russia? Especially if you consider that the 30’s warming was certainly higher in magnitude……
Diametrically opposed climate study conclusions. Does that have a human thumbprint or is it just a matter of natural variability?
The point of the paper was to call for more research and tap into the AGW bucket , so it was a ‘success’ quality had bugger all to do with its about letting others know the authors are ‘on side ‘
The planet has been warming naturally along the same trend line since the LIA. The warming trend is not accelerating [green line]. In fact, nothing unusual is happening; there have been droughts somewhere on the planet for as long as history has been recorded. This is just more cherry-picked grant trolling by Rahmstorf.
In the summer of 2010 I traveled to Russia(by car from the Netherlands up and down over 11000 km) and stayed there for almost 3 months. In South Russia the view of the sky was limited at night (hazy-smog or water?) in comparison with other years, it didn’t cool off as usual. When I arrived in may in Moscow it was clear but when I returned early august it was unbearable of the smog caused by the forest fires over a vast area, from Voronezh up to Moscow. The situation lasted over this period of time. I wonder if they investigated this unusal situation in their study.
Rahmstorf is becoming an asset!
I am reminded that Eduardo Zorita proposed Rahmstorf to be banned from future participation in IPCC assessments. See http://noconsensus.wordpress.com/2009/11/27/357/
Banning Mann and Jones is perfectly reasonable. I didn’t know why Zorita wanted to ban Rahmstorf also, but he must have a reason!
As McIntyre often says, “You have to keep your eye on the pea” with the climate gang. My eyeball regression gives a cooling trend of -0.1 degrees if you start from 1890 (but R^2 < 0.01), in accord with Dole's no significant trend since 1890. But alas if you start from 1910, you get a 0.4 deg warming.
Always keep your eye on the pea. The shell game continues.
I really don’t think you get how science works. Rahmstorf’s paper is a criticism of Dole’s paper (the NOAA paper you linked to). Dole found that the Russian heat wave could in no way be linked to global warming. Rahmstorf found otherwise and pointed out a flaw in Dole’s analysis. There may or may not be a flaw in how Rahmstorf crunched his numbers, but in science we go back and forth through the peer-review process until it’s sorted out. The fact that the Rahmstorf paper doesn’t agree with your pre-conceived convictions is no reason to call it “untrustworthy”. What sort of scientist are you?
And yet, in this peer-reviewed paper (http://www.agu.org/pubs/crossref/2011/2010GL046582.shtml), this statement was made in the abstract:
“…Analysis of observations indicate that this heat wave was mainly due to internal atmospheric dynamical processes that produced and maintained a strong and long-lived blocking event, and that similar atmospheric patterns have occurred with prior heat waves in this region. We conclude that the intense 2010 Russian heat wave was mainly due to natural internal atmospheric variability…”
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L06702, 5 PP., 2011
doi:10.1029/2010GL046582
Oh, well. Let the battle begin…
Thanks for your pointing this out, Dr. P., and for your analysis.
Gosh … I guess that means that Rahmstorf has proven the globe is warming.
Didn’t he realize that BEST beat him to the punch?
However, I don’t get it. He says that when numbers of extremes go up “in proportion to the ratio of the warming trend to short-term standard deviation.”
Without the paper, I don’t have a clue what the second one means, what is “short-term” standard deviation (SD), what is the length of the term, and why use that rather than regular old standard deviation.
In addition, I don’t understand the units of the ratio. SD is in degrees. Trend is in degrees per year, or per decade, or per century. So Trend (degrees/year) divided by SD (degrees) leaves us with units of ? per year … that always makes me nervous.
One method to investigate such a claim is to look at the extremes. For example, if there is no trend, then the ratio Trend/SD is zero, and the relationship would indicate that there would be no extremes at all … which makes no sense. So at least that much of their claim is in doubt.
More to the point, however, I don’t see how that adds to our store of knowledge. The only people who find heat records surprising in a generally warming world are AGW supporters. They’re the ones who are always on about how “seven of the warmest years are in the last decade” and like that, as though it were a surprise. The rest of us know what Rahmstorf has so laboriously established. In a warming trend, you’ll get more heat records, particularly in recent years … duh.
So yes, R&C have succeeded in verifying the blatently obvious. What I don’t understand is why anyone would either be surprised, or would care. It’s like the BEST results that verify that the world is generally warming … so what, we all knew that.
In the same way, the R&C results verify that in a warming world, we’d expect to see more high temperature records broken … so what, we all knew that.* It would be interesting if that didn’t happen … but since it did, including in Russia, it’s banal.
w.
* Well, except for the AGW supporters who are in a lather about the number of top-ten years in the recent decade. They didn’t know that. Maybe the paper is written for them.
80% probability? p=0.2?
What an incredible abuse of statistics.
Richard Saumarez says:
October 26, 2011 at 12:35 pm
You heard about the “New Math” that swept our schools in the 1970’s?
This is the “New Statistics”, that swept the mainstream AGW scientists in the 1990’s.
All the best,
w.
Re Garrett says: 12:28….What sort of scientist are you?
Actually it was Dr. Roger Pielke Jr, who used the term “untrustworthy”. You ask what kind of scientist are you? (Pielke or Watts?) You seem to suggest we should all remain quiet while this disagreement is sorted out in the peer review process.
But that is not how science oriented blogs work. We are all free to comment on the strengths and weaknesses of any published paper, whether we are scientists to your liking or not. That is, in my mind, a wonderfully enlightening and refreshing way to participate in science,
Dr. Pielke, Jr says there are flaws in the Rahmstorf paper. You say there may or may not be flaws in it. What don’t you address the issue that Dr Pielke raised? Try it, I think you will find it’s rewarding. Certainly more rewarding than suggesting Dr. Pielke and we have no right to comment.
jjm gommers says:
October 26, 2011 at 12:22 pm
“In the summer of 2010 I traveled to Russia(by car from the Netherlands up and down over 11000 km) and stayed there for almost 3 months. In South Russia the view of the sky was limited at night (hazy-smog or water?) in comparison with other years, it didn’t cool off as usual. When I arrived in may in Moscow it was clear but when I returned early august it was unbearable of the smog caused by the forest fires over a vast area, from Voronezh up to Moscow. The situation lasted over this period of time. I wonder if they investigated this unusal situation in their study.”
You musn’t muddy their ‘theoretical approach’ with mere observations!
5% would be a normal threshold. 2.5% if the test is two-tailed. “80% chance” is the same as saying non-significant, isn’t it?
If looking at trend/stdev over the short term, then if there’s no variability, each year is a record, so long as there’s a trend (imagine a straight slope). On the other hand, if there’s a trend hidden in a big bucket of variability, there aren’t so many records. Bit of what you might call a “no-brainer”.
I need to think about this. I guess they’re not referring to summing the actual extreme temperatures, but mean the actual events, i.e. “the count of warm and cold extreme events…”. Call it a language issue.
If that count goes up or down with warming or cooling, that implies we are neither warm nor cool now, or at the very least extreme events leave the trend in the noise.
Given that we are near the peak global temps, I don’t see how that fits. Perhaps the paper makes it more clear.
I believe this is called frequency, measured in Hertz.
No, I have no idea what Rahmsdorf is talking about either. It’s startling that these sort of papers pass peer review while critical papers get the full abuse treatment.
Does the same reasoning work for an extreme cold weather event? If the 2010 Russian summer heat wave indicates a high probability of “a background warming trend”, wouldn’t a winter cold wave indicate a high probability of a background cooling trend? (Silly me. I forgot that extreme heat and extreme cold are both indicative of a warming trend.)
Yup. Clear evidence of a warming phase after a long cool phase following a warm phase following a cool phase following a warm phase etc. Incontravertible. The author’s have won me (V Sarc).
You can get an uptrend ( or a down trend if it suits your purpose) out of a sine wave if you start your linear fit at a down ( or up) phase and finish it at an up ( or down) phase. Only someone with no idea of the actual mechanism at work and no idea generally would use a linear fit to clearly oscillating data . Or a fraudster.
I have a paper on sea level rise that basically does this ( The Sea Level at Port Arthur, Tasmania, from 1841 to the Present, J. Hunter et al, GRL, Vol. 30, No. 7, 1401, Apr. 2003 ) and it sits along side the hockey schtick in my pantheon of nonsense as the gold standard for the cretinous behaviour of some warmistas. I think I have found a third icon for my altar for the adulation of the ridiculous.
Why don’t these turkey’s just stand on their heads or go about naked when they want attention?
They never heard from jet-streams slowed down by less sun activity and missing UV-radiation heating normaly the upper athmosphaere.
Rahmstorf a scientist ? far away…
Amazingly these papers are published and these authors are still enjoying a career…
Ursu’s Augustu’s;
It’s an opening shot in debasing the test for significance from a risible 95% to an outrageous 80%.
___
Grammarnasty/ Abandon the use of all apostrophes. You have no clue. /Grammarnasty
It looks like Pielke Jr. has Rahmstorf over a barrel at his blog and at RC. One commenter at Pielke’s found that McIntyre had already dissected the padding-smoothing issue of another of Rahmstorf “non-linear-linear-trend” thingy’s, which it looks like R. might have to come back with to try to explain why he didn’t include the 1880-1910 data, “because it’s not linear” or “there is no trend back then”, or something:
http://climateaudit.org/2009/07/03/the-secret-of-the-rahmstorf-non-linear-trend/
I’m getting the idea that in regard to the method the “science” of mainstream Climate Scientists employs, its stats are just about equivalent in value to its verbiage: anything goes and it always proves “or else we’re all gonna die!” Unprecedently!
sigh…”So much to shovel, so little funding remains…cursed Teapartiers!”