People send me stuff. This one reminds me of a famous wrong way:
Hi Anthony
Today we had some rumour in the Dutch media due to a paper by a couple of econometricians which projected dramatic warming. Ross McKitrick discovered they had used a wrong dataset; We blogged about here: http://climategate.nl/2010/03/09/four-degrees-warming-in-2050-oops-you-used-the-wrong-dataset/It would be nice if you could post it on WUWT as well,cheersMarcel CrokScience writer
This morning, there was lot of noise in the Dutch media (unfortunately in Dutch only) about new research that was claiming a dramatic warming of 4 degrees in 2050. The news report quoted Dutch econometricians from the University of Tilburg. They had done a statistical analysis of temperature data and the influence of CO2 and solar radiation and concluded that aerosols masked much more of the warming of greenhouse gases than previously thought. This also means there is more warming in the pipeline for the future if the trend of global brightening, that has been detected by researcher Martin Wild of ETH in Zürich, will continue in the coming decades. They also draw policy conclusions from their research stating that in order to avoid more than 2 degree warming more drastic measures are to be taken. This news was copied by many Dutch news outlets.
Detection
Although at first I could not figure out if there was a paper behind the news article and whether or not it has been accepted for publication (I still don’t know), I finally determined it had to be this paper: http://center.uvt.nl/staff/magnus/wip04.pdf
I decided to pass the paper on to Ross McKitrick, who, as many of the readers know, published two interesting papers (here and here) on the influence of different economic parameters on the pattern of warming at the surface. Within hours McKitrick came back with an interesting finding which makes any detailed discussion on the paper let’s say… irrelevant.
Remember, their study is an attribution study depending on long term trends in temperature measurements. For their study they use a rather obscure CRU dataset: CRU TS 2.1. You can find its documentation below. The webpage reads:
The CRU TS 2.1 data-set comprises 1224 monthly grids of observed climate, for the period 1901-2002, and covering the global land surface at 0.5 degree resolution. There are nine climate variables available: daily mean, minimum and maximum temperature, diurnal temperature range, precipitation, wet day frequency, frost day frequency, vapour pressure and cloud cover.
Read the documentation
There is also a peer-reviewed paper behind CRU TS 2.1: Mitchell and Jones, International Journal of Climatology, 2005, so that’s OK. However, if the authors had just cared to go through this webpage in some detail, they would have found a link to this page:
It says:
Q1. Is it legitimate to use CRU TS 2.0 to ‘detect anthropogenic climate change’ (IPCC language)?
A1. No.
CRU TS 2.0 is specifically NOT designed for climate change detection or attribution in the classic IPCC sense. The classic IPCC detection issue deals with the distinctly anthropogenic climate changes we are already experiencing. Therefore it is necessary, for IPCC detection to work, to remove all influences of urban development or land use change on the station data.
In contrast, the primary purpose for which CRU TS 2.0 has been constructed is to permit environmental modellers to incorporate into their models as accurate a representation as possible of month-to-month climate variations, as experienced in the recent past. Therefore influences from urban development or land use change remain an integral part of the data-set. We emphasise that we use all available climate data.
If you want to examine the detection of anthropogenic climate change, we recommend that you use the Jones temperature data-set. This is on a coarser (5 degree) grid, but it is optimised for the reliable detection of anthropogenic trends. For precipitation trends, use the Hulme data-set (5 degree grid or 2.5 x 3.75 grid). There are few alternatives to Hulme in the first half of the 20th century; later, to include the oceans use the Xie and Arkin data-set; for the last 25 years you could also use the GPCC data-set.
Yikes. This dataset is not to be used for the type of study performed by these econometricians. Never. Period. Don’t use it. Lies, damned lies, statistics and very sloppy science.
“…can someone please tell me what an econometrician is?”
Someone who figures out how much it costs to wire a weather station?
🙂
Ah. This would be a gray paper then? We know how that turns out. AGW researchers still email nasty stuff to each other about contrarians and get papers published on the net or their comments quoted in magazines, in shades of gray, as if they haven’t been noticing the 700 lbs gorilla in the room.
For those of you confused about the whether the CRU TS 2.0 anthropogenic detection caveat is applicable to the CRU TS 2.1 dataset, please read this:
http://www.cru.uea.ac.uk/cru/data/hrg/timm/grid/CRU_TS_2_1_text.html#Guidance
Specifically, this part:
“The issues involved in using CRU TS 2.1 for time-series analysis are addressed more explicitly and fully; this guidance was originally given for CRU TS 2.0, but it applies equally to CRU TS 2.1. We recommend that all users who intend to examine climate change using this data-set should consider the issues carefully before beginning their work.”
The blurb links to the aformentioned CRU TS 2.0 anthropogenic detection caveat. So yes, it applies to both the 2.0 and 2.1 datasets equally.
I love reading these posts. Not only do I read about the “inside baseball” stuff, but my vocabulary is always increased. Today I learned…
codswallop
boffin
Here is another critical error they made which completely undermines their entire case (independent of the CRU TS dataset issue), on page 23 they state:
“Since CO2 is well-mixed in the atmosphere (Forster et al, 2007, p. 138), we may assume that CO2 is the same for each weather station and hence we don’t require information at station level for CO2.”
Wrong. First of all, CO2 is NOT well-mixed in the atmosphere. Even NASA’s own chief scientist at JPL, Dr. Moustafa Chahine, said in a recent NASA press release that “contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere”[1]. How much clearer of a signal do these guys need?
Second, how can anyone assume that CO2 levels are “the same” across weather stations? If that were true, why would it be necessary to locate CO2 monitoring stations in the most remote and inhospitable regions of the Earth?
1. http://www.jpl.nasa.gov/news/news.cfm?release=2009-196
Weather will be playing quite a role in our food supplies around this planet with sudden weather annomolies and cooling trends that inhibit plant growth.
Food prices are going to go way, way up!
Wow, we have bad politicians, wrecked economies, religion and Al Gore.
BOY, Do I feel depressed!
JimAsh (16:48:17) :
™ (option+2)
Can’t trademark without the Trademark Trdemark ©
Ctrl-Shift-U-2122 -> ™
and to toss it in…
Ctrl-Shift-U-00A9 -> ©
What keystroke combo is “option 2”? Ah heck, where is the “option” button anyway?
Terry Kette (19:22:52) :
I love reading these posts. Not only do I read about the “inside baseball” stuff, but my vocabulary is always increased. Today I learned…
codswallop
boffin
You need to start reading The Register. Your vocabulary will increase immensely. Just not necessarily in a completely good way…
In other Dutch news we learned that the former minister of milieu J. Cramer (old hag) paid half a million Euro’s to a spindoctor called “Maurits Groen” and his bureau “Milieu en Communicatie” (http://www.mgmc.nl/) in the running up to Copenhagen, basically she was handing out free money. My money that is.
Arn Riewe (16:33:02) :
I certainly know of economists, but can someone please tell me what an econometrician is? I notice as I type it the WordPress doesn’t seem to know what it is either.
I had to use my Mad Google Skillz™ to figure it out, because “econometrician” went over my head at Mach 2. Evidently, an econometrician is someone who specializes in developing statistical models to elucidate the principles of economics.
‘Nother words, it’s just one more episode of *economists* pontificating about physics…
kadaka,
And here I thought I maybe I was the only El Reg fan – Ars Technica is good too (lots of overlap), but the pro-AGW side of the coin.
Daniel H,
NASA really should have retracted that press release. Their “lumpy” CO2 distribution was less than 8 (maybe 6 if I recall the post and discussion here correctly) ppm in variance. We’re talking very minor variances (2% or less). Unfortunately hype seems to trump clarity with science these days… NASA should be better than that.
@Arn Riewe (16:33:02) :
I could be wrong, but I suspect that an econometrician is an expert on the economy as much as a cosmetician is an expert on the cosmos.
BTW – as much as everyone loves to hate economists, if used correctly econometrics can be very useful for finding relationships in data sets and analyzing their usefulness. Check out the post on mathematical analysis of CO2 that was posted a week or two back. Really intesting… to me at least
It is, in many ways, much more advanced than the methods used in climate science… but at the same time, a good statistician can make the results say whatever they want.
You have to start out with good data, your methods should be predetermined, and the results need to speak for themselves and not be spun. I’m not sure any of those apply to climate science.
save this! It will be “re-adjusted” Its not possible!
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
I’m not sure if the Dutch study had used Jones instead of CRU TS 2.1, the findings would have been much different. They conclude that ignoring local dimming underestimates the greenhouse effect.
http://center.uvt.nl/staff/magnus/wip04.pdf
Daniel H (20:11:11) :
Here is another critical error they made which completely undermines their entire case (independent of the CRU TS dataset issue), on page 23 they state:
“Since CO2 is well-mixed in the atmosphere (Forster et al, 2007, p. 138), we may assume that CO2 is the same for each weather station and hence we don’t require information at station level for CO2.”
Wrong. First of all, CO2 is NOT well-mixed in the atmosphere. Even NASA’s own chief scientist at JPL, Dr. Moustafa Chahine, said in a recent NASA press release that “contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere”[1]. How much clearer of a signal do these guys need?
Second, how can anyone assume that CO2 levels are “the same” across weather stations? If that were true, why would it be necessary to locate CO2 monitoring stations in the most remote and inhospitable regions of the Earth?
1. http://www.jpl.nasa.gov/news/news.cfm?release=20
==============================
As the authors of the paper say:
“What matters is whether small deviations from our assumptions will cause large or small changes in our conclusions.”
Tim C (17:34:46) :
“The “paper” is dated 1st September 2009, probably produced for the Copenhagen love-fest.”
Okay;
Copenhagen Snow-Fest ™
CRU is saying that their data TS 2.0 is unadjusted. “The grids are based on raw station data.”!
So what adjustments do you think they should have made?
Nick Stokes (23:25:26) :
CRU is saying that their data TS 2.0 is unadjusted. “The grids are based on raw station data.”!
So what adjustments do you think they should have made?
Better ones than they have been making!!
Arn Riewe
Ecomometricians try to model economic situatuations. I understand that econometricians’ models are better than nothing if you have to decide government policy – e.g. do you build another runway at Heathrow Airport.
But how can it be possible to model such a chaotic system as climate? Isn’t climate the ultimate chaotic system? Is it possible to model chaotic systems?
Econometry is a technique; you can’t blame a technique for it’s wrong application. 95% percent of all papers are junk across all disciplines. I don’t blame computer science for the 95% junk papers about edge detection; what counts are the 5% good papers that form the basis of todays image processing technology. And they’re as good as gold.
Sturgeon’s law applies as usual, and it obviously also applies to newspapers.
Thermageddon is upon us. Doom, doom and thrice doom!
But seriously, if temperatures do continue to remain stable (or even start to decline) will the public buy a new narrative about the dangers of Global Cooling like we had in the 1970’s and early 80’s?
Arn Riewe (16:33:02) :
“I certainly know of economists, but can someone please tell me what an econometrician is? ‘Nother words, it’s just one more episode of *economists* pontificating about physics…”
An economist is a person who, seeing something working well in practice, wonders how well it will work in theory.
Look at it from the bright side: the data set is specifically set up to facilitate study of past “climate” on land and in particular not “corrected” for the urban heat effect.
This means that the authors have done us all a favour because what they have actually measured in detail and proven is the urban heat effect and extrapolated it to 2050. We now know how to correct the raw climate data reliably.
Rejoice!
Since mid-40ties, net global temperature increase is 0.3 deg C (per hadCRUT). Without UHI and data manipulation, it should be even less.
Based on WHAT did those pseudo-scientists forecast 22-times higher rate of temperature increase in next 40 years than up to now?? Not speaking about sober prediction by orthodox German climatologist Mojib Latif, who expects several decades of cooling, or at least stagnation of global temperatures.
Some people simply has no common sense.