It includes the comment, “No statistically significant trend can be discerned from the [HadCRUT4] data.”
I’ve seen other comments that point out the variability of the data points, in terms of uncertainties, and also the recent study about removing temporary negative and positive influences on temperature, showing a definite continuing warming trend.
Is there any chance of a comprehensive rebuttal of the above blog entry?
This is a favourite of the fake sceptics. It is what I call cherry picking your starting point. They’ve started in 1997 not because they are looking for a 15 year window but because 1998 was a very hot year due to a massive el nino effect.
What do the columns, except col 1 which is obviously year, represent in ‘hadcrut4_annual_ns_avg”? There are 11 of them so can’t be month, I need to know as I want to do a series of graphs showing how choosing your stating point aaffects the regression line slope (dramatically) if you only concentrate on the last two decades.
The burning issue everyone will surely be wanting to hear is ‘how much has HadCRUT4 adjusted recent anomalies from HadCRUT3?’
The answer is that up to 2010 (where HadCRUT4 presently ends) it gives an increase of some 0.04 deg C.
This link should lead to a graph of HadCRUT3 & 4 10-year rolling averages.
I would be suspect of anyone who chooses particular starting (or ending) points to show exceptionally low (or high) warming trends. While the statement is true, it should be viewed in light of the longer data trend. Temperatures have been rising since the 19th century, with periods of greater and lesser warming (even cooling). I have not analyzed the new CRU4 data yet, but have done considerable work with CRU3. While the claim by some that the trend is negative over the past decade is true, the claim by others of the high trend of 0.18C/decade for the previous 30 years is also true. But as Paula mentions above, these are cherry picking. Over the long haul (130+ years), the temperature has risen at an average of 0.6C/century, with the previous high and low periods, preceded by similar high and low periods.
> I have not analyzed the new CRU4 data yet,
> but have done considerable work with CRU3.
Well, that’s a new claim. What work does “Dan H.” claim to have done in this field? “Dan H.” claims expertise in the science.
This seems an extraordinary claim. Can it be supported?
I’m not asking our hosts to break his anonymity, but to vouch for his claim that he’s done work in climatology. If we’re to trust people posting under pseudonyms, claiming expertise, someone’s got to vouch for them.
Anybody can use wood for trees to make linear plots which don’t show any statistical relevance, I imagine that Hank had hopes that “working with” the data meant something more, like, for instance, unlike everyone else you’ve managed to show that a 10-year cherry pick shows flat temps with statistical significance, just as a 30-year plot shows a rising trend with statistical significance, therefore vastly changing our knowledge of what statistical significance means in global temperature time series.
Sadly, though, it appears that you’ve fallen short of my guess at Hank’s expectations.
Not that this is anything new, you’ve played this game before.
With regard to 15 year trend, it’s a test of whether or not global warming has stopped. The drawback is that it’s a completely unreliable test. And it’s very easy to show that.
Pick a period over which there’s agreement that warming occurred. So, the globe warmed between 1950 and 1999, say, and we all agree on that. Take (in my case) the GISS series, apply the 15 year trend test successively to the years 1950 … 1985. How reliably does the test show that warming is occurring?
Answer: It’s substantially less reliable than flipping a fair coin. For 14 of 36 cases, the trend is positive with P < .05. (With no adjustment for autocorrelation, because that's how the dummies usually run it.)
First observation: The test is modestly less reliable than flipping a coin if it is reported fairly, year after year. But it's only wide reported when it shows that global warming "has stopped". Once you've accounted for the "publication bias", it's totally unreliable as observed. I would call it a "stopped clock", but that does disservice to the clock, as even a (US) stopped clock is right twice a day.
Second observation: For as long as you live, in slightly more than half the years, you'll see somebody telling you that global warming has stopped, based on that test.
Comment by Christopher Hogan — 17 Apr 2012 @ 11:27 AM
Science and math can be such a pain. As long as you don’t need to be concerned about the science or math there are an almost infinite number of ways to prove that global warming/climate change doesn’t exist.
Some people in the Netherlands also were complaining that there was no significant warming over here over the last 15 years. When investigating the homogenised The Bilt series (KNMI), this is correct: no significant warming over 1997-2011. But two years ago there was significant warming over 1995-2009. Looking at the last decades, of all possible 15-year periods around half had significant warming and the other half didn’t.
This indicates that warming isn’t a monotone process; no surprise at all. Aside, the last time there was significant cooling over 15 years was 1911-1925.
But why looking at just 15 years? The WMO defines ‘normals’ as ‘Period averages computed for over a uniform and relatively long period comprising at least three consecutive 10-year periods.’ So why not looking at 30-year periods when the data is available?
The Bilt (hom.) had significant warming over the years 1982-2011. The last time there was no significant warming over 30 years was 23 years ago (1959-1988).
At #4 Paula Thomas asked about the columns in HadCrut data sets. As in previous HadCrut data sets, column 1 is the date and column 2 is the anomaly estimate (relative to baseline). The rest of the columns are various 5-95% uncertainty ranges (given in pairs).
I meant to add in the energy spent in trying to open the door of knowledge by those who have better things to do as well to what is turning into a perpetual motion machine – though perpetuity is ill served by this nonsense.
If the right points are picked both before and after the huge El Nino of 1998, the slope line can be perfectly flat either way. That is because La Ninas around 1998 balance things out.
(From a recent Spencer thread)
Oddly enough, they were unable to recognize the problems with their approach…
Doesn’t this fall into the “it’s not a bug, it’s a feature!” class?
I remember reading a Master’s student’s thesis proposal which said that he would try a variety of statistical techniques until he found one that showed the results were significant. I was more worried that his supervisor had not seen anything wrong with the proposal…
After following the topic from street-level for about two decades, the first funny part about the ‘stopping’ argument is that temps keeps ‘stopping’. Every decade there’s been a claim that “it” is over, and every decade new global peaks are reached. It’s like the broken turn-signal signal joke.
The second funny part is the focus on cherry-picking a start point, when the real card-trick is picking the end-point. The volume level of the stoppers is directly proportional to the inverse of current ENSO conditions. Add a couple of rough, cold anomalies in Europe when the Jet Stream short-circuits and, voila – the perfect low end-point to hook up to 1995, 1998, and December 2001.
I see you, for one, picked up my assertion that anyone can cherry-pick the data to post what they want to show. Some people have even gone so far as to change the slope of the past 10 (or 15) years to match the previous 30. Looking at the entire dataset, shows the folly in these type of displays. I really do not concern myself with Hank’s expectations.
1 Tony asks, “Is there any chance of a comprehensive rebuttal of the above blog entry?”
Sure. The point the post makes (but also tries to hide) is that a 15 year period without warming is not a refutation of theory, but it REQUIRES AN EXPLANATION. It then drops the ball by not looking for an explanation. Well, “not looking for” is probably not right. Far far FAR more likely is that they knew about Foster and Rahmstorf 2011 (which completely answers your question) and chose to try to fool you by not mentioning it. So, google F&R, or just look it up here on RC. After that, come back and tell us what you think of the integrity of your source.
Yes, this is about integrity, not scientific disagreement. Otherwise they’d have said, “F&R2011 is wrong because _____”.
“I meant to add in the energy spent in trying to open the door of knowledge by those who have better things to do as well to what is turning into a perpetual motion machine – though perpetuity is ill served by this nonsense”.
I think this sentiment is worth more than a passing reflection and certainly deserves to be made known to a wider audience. Well said!
Tony Weddle @1
Further to comment from Jim Larsen @35, the piece you highlight is simply republished ‘work’ by “Dr David Whitehouse, science editor of the GWPF.”
Myself, I didn’t realise the GWPF had such an editor. There is no announcement of it on the GWPF website. And anyway, the GWPF claim not to hold any position on science (but then claims made by the GWPF are very seldom borne out by reality).
I wonder if Whitehouse is using shorthand to describe his position at the GWPF. He has up until now been “…a former BBC Science Editor and a scientific adviser to the Global Warming Policy Foundation.”
Given it is supposed to be an educational charity, my own quite extensive researches (most recently published here) demonstrate the GWPF to be a singularly untrustworthy organisation.
The conclusions inferred by Whitehouse from his findings are pretty impossible to support unless you interpret”…great uncertainties in our understanding… to refer to ‘GWPF understanding‘. Note also how Whitehouse cannot wait for a 2011 figure for HadCRUT4 and so makes up his own figure. However well argued this act, it has to ring alarm bells – “Idiot on the lose!”
Simon Abingdon, I’m pretty sure I’m not flattered. My sentence was rather gummy and the point could easily be reversed, which I assume was why you admired it. If you’ve had a change of heart, I’d like to know. For some reason, you find my amateur efforts easy to target, and provide lots of honey in the trap.
Let’s start with the original to provide some context:
“If one could harness the energy spent by fake skeptics bolstering their prejudices, it would provide a great deal of “clean” energy, though the pollution of time wasted doing so might not be offset.”
I then suggested that I had failed to mention real scientists were being forced to waste their energy repeating obvious truths to try to get through the muck rather than continuing their excellent and necessary work finding out more about the truth embodied in our planetary circumstances.
Brian Dodge @~33 – Speaking of amateurism I had fun changing the end year to later than 2005 and changing the database (from HADCrut3) which provided some even stronger illustrations. Thanks. Don’t even need to know much science to see the obvious there.
Kevin McKinney @~36 – exaactly: so far, 4 cites of the elevator graph. Once more into the breach, dear friends, trying to get the truth out. There are none so blind as those who *will* not see.
Comment by Susan Anderson — 18 Apr 2012 @ 10:08 AM
Thank you for being so observant. Sometimes, I think the reactionary response is too quick, and the full meaning is missed.
If only. Dan H. muddies the discussion by confusing two different issues.
One: sufficient data to have good probability of detecting a trend — not making claims using short time spans.
Two: assessing changes in forcings associated with changes in climate — using data sufficient to do the statistics.
If you “use all of the data” you can’t detect any change in trend from forcings known to make a difference (e.g. sulfate aerosols, which peaked in the 1940-1970 range from US sources and again later from Chinese).
Using “all the data” precludes detecting change during the time span.
Cherrypicking short term data precludes confidently detecting change.
“… “Dan H.” stated that what mattered was the long-term trend, which was a steady increase at a rate between about 0.006 and 0.0075 deg.C/yr ….” at Tamino’s and particularly November 8, 2011 at 12:24 pm
None of us want climate to change as fast as it’s happening; rather than grasping at straws, we inspect them — really closely — lest we be fooled by false hope and fake assurance from business-as-usual PR guys.
Folks, Dan H. in #9 was (by my reading) pointing out the folly of cherry-picking, not endorsing it. And I would agree with him on that point.
No, he’s claiming that an interval that shows a statistically significant trend is “cherry picking” in the same sense that chosing an interval that does not show a statistically significant trend is.
In other words, statistical significance (and by extension, statistical trend analysis) is worthless.
He then moves on to say that the only trend that’s significant is the last 130 years, which he chooses because it conveniently leaves out most of the additional forcing due to mankind’s dumping of CO2 into the atmosphere, and various other reasons put forth by Hank above.
Go read the Tamino thread devoted to Dan H’s obsfucation. I don’t see how anyone can read that and still believe that Dan H is just innocently warning against cherry-picking. Tamino’s a professional statistician specializing in time-series analysis, BTW …
Now including CRUTEM4 data
12th April 2012:
Rather late to the party, but WFT now includes the new CRUTEM4
dataset from Met Office Hadley and East Anglia CRU.
Here’s a quick comparison of CRUTEM4 and CRUTEM3. CRUTEM4 seems to have a markedly higher recent trend (2.8°C/century) than CRUTEM3 (2.2°C/century).
Draw your own conclusions!
You may have a point that the enhanced CO2 addition of recent times may make a huge difference. Breaking the long term into 30-year time intervals starting in 1880, yields temperature changes of -0.21, +0.46, -0.05, +0.51, and -.13 C/decade (althought the last interval has only 12 years of data). Alternatively, we could divide the temperature record into four equally spaced intervals based on CO2 rise. The resulting time periods would be 1880-1956, 1956-1980, 1980-6/1997, and 6/1997-2012; with each time period representing a 7.8% increase in atmospheric CO2. The temperature changes over these four periods are as follows: +0.05, +0.03, +0.09, -0.04 C/decade, with each succeeding range have a larger uncertainty, due to the shrinking time interval.
There are many nuances in the temperature record, and there are many more explanations as to there causes.
BTW, the Tamino thread is heavily one-sided, as he refused to allow me to respond.
Dan H. Am I reading this right? First you claimed to have done “considerable work” in climate science. In response to Hank asking for evidence to back this up, you link to a single graph on Paul Clark’s site with cherry-picked data. Once called out on that, you spin it to mean you are warning people about cherry-picking? What “considerable work” have you actually done? I take that phrase to mean either “work worthy of consideration” or “a substantially large amount of work”. I don’t see how you link qualifies as either. If making a single graph with 4 time series in it at WoodForTrees.org counts, then I and many others have done much more than “considerable work”, yet I would really characterize it as “some investigation.”
KR @39, the reason you see many people having a “knee-jerk” reaction to Dan H’s posts is because he claims stuff like this. He posts in an authoritative voice, yet you completely misunderstands the subject he is discussing. We only need to look back 2 months ago for a glaring example, to when he tried to use the PDSI to make a point about droughts. As soon as it’s pointed out that he flipped the sign and read the graph backwards, he drops that and acts like it is not a worthy source of information, the source he provided to back up his claims. he is not interested in understanding the real world, he is interested in backing up his talking points.
Dan H has ruined his credibility as someone open to an honest discussion, and has proven his inability or unwillingness to do the actual work required to gain an understanding of the subject matter he discusses.
Comment by Unsettled Scientist — 19 Apr 2012 @ 11:48 AM
Unsettled Scientist – My initial response was based strictly upon Dan H.’s first comment on this thread, which I thought might be read as a reasonable response. Given the context of his following posts, let alone the discussion on Tamino directly upon some of his assertions, I certainly understand the reactions he’s received.
However – whether or not I agree with what a particular person has written or opined, I think it’s still appropriate to read something new from that person in that context. My expectations might be quite high or quite low based upon experience – but even in the worst case, a stopped clock is right twice a day…
Sorry, I have a typo in my previous post, it should read “… yet *HE* completely misunderstands the subject he is discussing … ” not you where I have fixed it to he. Silly pronouns. I just wanted make sure KR didn’t think I was saying KR completely misunderstands the subject matter, just that Dan H. has a history of presenting data that completely negates his assertions while not even realizing it. So we have to be careful if we try to ascribe some rational deeply thought out analysis to his posts.
Let us not belabour this Dan H. situation. He comes with a pet theory.
CO2 he says has been rising pretty much exponentially. The theoretical relationship between CO2 levels and resultant forcing from CO2 is logarithmic. So the resultant temperature rise from such forcing could be argued to be linear.
Here lies Dan H’s fascination with % rises of CO2 & coincidental rises in global temperatures which he attempts to construe as linearish. Add in a simple wobble and, hey presto, all this bother about the global climate being some sort of complex system that is beyond the wit of mere mortals to comprehend, it simply evaporates to nothing under the clinical analysis provided by none other that Dan H.
Who cares about 1850-2010 HadCRUT4 when the sums have been done for 1880-2012? Stuff doesn’t matter when you’ve got a handle on the real truth.
And if there are many other reasons for shifting global temperatures which would make a nonsense of such theorising, how can they be relevant in such moments of ephemeral self delusion?
You may be the first person that I have encountered here with an open mind. After our original argument, Tamino has simply decided to belittle my analyses, and encourage his cronies to do the same. Hardly open minded. Too many people are too quick to shout down anything that challenges their closely held beliefs. I welcome your input.
apparently of one leaves comments at the end of the “comments (pop-up)” section, the comments go directly to the bore hole. The button at the end says “say it!” rather than the “submit comment” at the end of the regular comment section.
Tamino did not belittle your analyses. He shredded them. He obliterated them. He showed them for what they were–absurd cherrypicks and misinterpretations or gullible swallowing of whatever tripe you read on denialist websites. It was beautiful.
Now you’re saying, “It’s just a flesh wound!” That makes my day.
Okay, I’m not a scientist but a concerned citizen with a “cut to the chase” question…
What’s the prognosis for say the next 50 years? Does anybody see any chance at all that the global population is going to wake up to reality any time soon? I would like a serious honest reality based opinion on what we’re in for in say the next 10 to 20 years. I don’t see any political progress being made. I hear a lot of scientific discussions and debate over data but NOTHING is happening that’s going to slow down or reverse Climate Change. Gavin???? Any ideas about what we’re in for or maybe how soon? Are we making any progress at all?
After our original argument, Tamino has simply decided to belittle my analyses, and encourage his cronies to do the same. Hardly open minded. Too many people are too quick to shout down anything that challenges their closely held beliefs. I welcome your input.
You sound just like one of those inventors of a perpetual motion machine after being smacked down by a physicist. “Belittled my analysis”. “Hardly open minded”.
You’re *wrong*. A statistician pointing that out isn’t close-mindedness.
A question from someone who does not know much about global warming.
Of the extra energy that stays on earth due to greenhouse gases accumulating in the atmosphere, what % stays in the “air”, what % goes into the oceans and where else does it accumulate (with % if possible)?
[Response: Something like 90% goes into the ocean (because the heat capacity of water is so large). - gavin]
Dan H. wrote: “After our original argument, Tamino has simply decided to belittle my analyses, and encourage his cronies to do the same.”
That’s a despicable lie, Dan H.
Tamino didn’t “belittle” your so-called “analyses”.
In fact, Tamino demonstrated beyond question that your so-called “analyses” are dishonest rubbish.
Why the moderators tolerate your blatantly dishonest, clumsily deceptive trolling has always been a mystery to me.
And it’s even more of a mystery as to why they would tolerate this creepy, sneering little attack on Tamino.
Comment by SecularAnimist — 20 Apr 2012 @ 10:07 AM
Pretty much EVERY DISCUSSION THREAD on this site lately has been dominated by Dan H’s deliberately, blatantly, sneeringly dishonest trolling. And there’s nothing remotely interesting about his trolling — nothing new, or challenging about it. Just the same, tired old dishonesty and cherry-picked graphs, over and over and over again. Just the same tiresome old garbage that deniers have been copying-and-pasting for years.
And now Dan H apparently feels free to escalate his boorish behavior into personal attacks aimed at Tamino.
Why do the moderators allow this one individual’s trolling to dominate the discussions on this site?
Comment by SecularAnimist — 20 Apr 2012 @ 10:14 AM
Dan H. – KR, You may be the first person that I have encountered here with an open mind.
It’s important to keep an open mind – but not one open at both ends, as stuff tends to fall out.
Having gone and read your posts here and on the Tamino thread, I must say I am, well, unimpressed by your arguments or methods.
I will continue to attempt to give new discussions proper consideration. But, being only human, and having finite time, I may give yours more careful, more dubious scrutiny – based on previous history.
73 — As I mentioned to Hank Roberts, there are “2″ Dan H.s — the moderators seem to see a value in permitting a small portion of his BS to appear outside of the Bore Hole, perhaps to illustrate the evolution of denialism.
As despicable as he appears to be, there’s a value to seeing his evolving arguments, if only to better combat them.
Thank you for the data; I have updated my spreadsheet, though I will also keep HadCRUT3. Oh, and someone should tell McIntyre so that he can file dozens of FOIA demands for the data, since it’s yet another opportunity for him to harass scientists, and then complain about the new data being kept secret…..
DNTTT, I like it. Over the years his ilk have increased their literacy and tone, which is not good. The truth is such a gossamer thing, easily trounced by multiple lies, especially clever lies believed by people who don’t even know they’ve bought garbage disguised as gold.
Science is a discipline and takes a lot of hard work and intelligence. Belittling scientists is a fool’s game played by far too many.
*DNTTT = do not train the troll
Comment by Susan Anderson — 21 Apr 2012 @ 12:05 PM
@Dan H. (#64):
You may be the first person that I have encountered here with an open mind.
Ha ha ha ha… ha (ROTFLMAO was just not good enough to express my open-jawed reaction to your ludicrously naive appraisal of the veteran RC readers’ reaction to yet more Dan H. attempts at obfuscation).
In my estimation, Walter Pearce has summed the situation up astutely: most of the Dan H. posts go the way of the Bore Hole ever since Eric (?) declared that intention. But some of them appear here as a useful illustration of the evolution of what deniers construe as ‘evidence’.