Tom Karl’s Trends Are Wrong – At Least in Slide 21
Guest post by Bob Tisdale
A number of bloggers on the WattsUpWithThat thread “Tom Karl’s Senate Dog & Pony Show – it’s worse than we thought, again” noted the curious errors in the trend lines in Tom Karl’s presentation to Senate. The one that stood out for me was slide 21, presented here as Figure 1. It showed the global land surface temperature anomalies and linear trends for the new (Version 3) versus existing (Version 2) Global Historical Climatology Network (GHCN) dataset.
http://i48.tinypic.com/4j4c60.png
Figure 1
First Observation: The slide title states the data is monthly, but the data illustrated are annual averages. Figure 2 is a graph of monthly Global Land Surface Temperature anomalies presented by the NCDC from January 1900 to April 2010. Monthly global land surface temperature anomaly data should look like that, with lots of month-to-month variation.
http://i45.tinypic.com/5k3xjp.png
Figure 2
Second, there are two linear trends listed on the Karl slide. Version 2 is noted to have a linear trend of 0.83 deg C/Century, while Version 3 is claimed to have a linear trend of 0.91 deg C/Century. But the trend lines are nearly identical and they present linear trends of approximately 0.75 deg C/Century, Figure 3. The trend lines are erroneous or the values listed for the trends are wrong.
http://i49.tinypic.com/28iyyhk.png
Figure 3
Trend lines of 0.83 and 0.91 deg C/Century should be noticeably different, as shown in Figure 4.
http://i48.tinypic.com/346at1d.png
Figure 4
And for reference, the NCDC’s Monthly Global Land Surface Temperature anomaly data, Figure 5, has a linear trend of 0.78 deg C/Century.
http://i47.tinypic.com/142a1b4.png
Figure 5
And the the NCDC’s Annual Global Land Surface Temperature anomaly data, Figure 6, has a linear trend of 0.77 deg C/Century.
http://i45.tinypic.com/v4qvxl.png
Figure 6
Makes one wonder. If a simple comparison graph with linear trends is so error filled…
SOURCES
Tom Karl’s Powerpoint Presentation is available here:
ftp://ftp.ncdc.noaa.gov/pub/download/Global%20Warming%20is%20Unequivocal%20TKarl%20May%206.ppt
A full-sized copy of Slide 21 is here:
http://wattsupwiththat.files.wordpress.com/2010/05/karl_senate_2010_pg21.png
The NCDC Land surface temperature anomaly data is available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
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Linear regressions are done on the data, not by putting a ruler on a crude graph from a power point slide. But do notice all the slopes are up. The world is warming.
REPLY: Oh puhleeze. If they can’t make a valid presentation slide to the Senate, what trust should we place in the data? If they eyeballed the slide creation rather than plotting it, then we can’t really say they were truthfully representing the data.- Anthony
Does not matter. If he had declared that the moon is made of robust green cheese the damage is done and they will never retract it. Glaring errors will be fixed under cover of darkness and for what the public hears they were that way all along. This is a staged event.
Again, speed or amplitude of warming (if there is one) is beside the point. What of that (alleged) warming is caused by human emissions of CO2? Where is evidence for that?
Andrew.
Will someone be able to pose the error to the Senate?
Mike,
Please explain the cooling between 1940 and 1980. Thank you very much.
I have a problem with Figure 4. Linear trends go through the point of means. So they should intersect in the middle, not at the beginning as shown. The basic point — that the slopes should be more visibly different — is a valid one. But the attempted illustration is not. Pick the midpoint of the time period, and then draw the lines through that point with slopes of .83 and .91, to illustrate the difference.
Faux Dr. Karl ought to start that trend from Roman warming period..
Mike says:
May 19, 2010 at 7:45 pm
Linear regressions are done on the data, not by putting a ruler on a crude graph from a power point slide. But do notice all the slopes are up. The world is warming.
——————
And how pray tell do you think they produced the slide. Do you think they did it free hand?
O’course….they might have. I do not think that it makes them look better if they did though.
Dang, not robust x2, not robustness x3, but now, because they got caught fibbing to the Senate(nothing will happen to them)….we’ll have to have the robustest x4.
All the slides show some warming. The world is warmer than when 1900 1700 1200? Who picks the starting point? The world has been warmer and cooler but purpose of this presentation was not that the world is warmer but man is the cause. Not that the earth has been warmer and cooler without mans inputs. Sounds arrogant to me.
Thanks for all you do at WUWT
REPLY: Oh puhleeze. If they can’t make a valid presentation slide to the Senate, what trust should we place in the data?
You’re using “the data” to critique the slide, aren’t you?
REPLY: No, the slide itself is erroneously self explanatory. -A
I think Mike is right. If you start at 1900, and end at 2010, you get a bigger number for the warming-per-century trend.
If the data are correct (big IF), then something on the order of 1°C of warming has occurred. But even if warming has occurred, that tells us nothing about what caused it, or whether or not it will continue, or whether that weather will be mostly good or mostly bad, or whether replacing carbon fuels with hyper-expensive alternative fuels will help or hurt … etc.
We probably ought to apply the precautionary principle, and be nearly certain of answers to those question, before we make any big changes. We do know with great certainty that the 1°C of warming so far didn’t hurt us at all, in fact the human race flourished as never before during that warming. So we can say with a fairly high degree of certainty that, even if we caused the warming, we still have something like another century to figure things out.
One century ago children died at alarming rates, mostly from biologically polluted water, famine was common place, and virtually no one had electric lights, air conditioners, automobiles, jet planes, computers, telephones, cell phones, microwave ovens, washers and dryers, flush toilets, sewage treatment plants, water purification plants, etc., etc.
We should be concentrating on improving the lot of those of us who still go to bed hungry, and who don’t have all the wonderful things we take for granted. In fact, shame on AGW advocates for taking attention away from that effort. We should be building power plants and infrastructure in the developing world, not trying to figure out how to make our power plants more expensive.
This GW debate rages in the absence of any real knowledge on the subject. If we had the answers to the important questions, there would be far less mind-numbing discussion.
Thomas
Tom Karl have something to do with the two sources on this?
http://content.usatoday.com/communities/sciencefair/post/2010/05/2010-is-warmest-year-on-record/1
Shearer says:
May 19, 2010 at 8:09 pm
‘Faux Dr. Karl ought to start that trend from Roman warming period..’
And we have been treading down hill since then. I feel a big chill coming.
Oh dear, that’s distressing. I would never have imagined that CLIMATE SCIENTISTS did such sloppy work.
Mike said: ” …. But do notice all the slopes are up. The world is warming.”
But, do notice that all “corrections” also go up. The upgoing temps and CO2 do not correlate.
The new version 3 will have whatever trend Karl and Peterson want it to have.
If they want it to be 0.91C per century, it will be.
To meet the 3.25C by 2100 projection, the warming rate has to more than double to 2.4C per century in the remaining 90 years so they have to start making those “adjustments” now. [Including oceans it will have to be even higher].
The final Version 43 adjustments to be made in 2094 will get them up to the trend unless someone stops these two starting now.
Mike says:
May 19, 2010 at 7:45 pm
At the rate of 1.0 C per century? So what.
Sea level data for 2010 now available at http://sealevel.colorado.edu/results.php.
Talked with one of the guys there a couple of weeks ago asking when 2010 would be included in charts and data. He said it was on its way.
He was right.
Nice guy.
Mike says:
May 19, 2010 at 7:45 pm
Linear regressions are done on the data, not by putting a ruler on a crude graph from a power point slide. But do notice all the slopes are up. The world is warming.
Please at least be a little scientific when here if you are capable. Linear regressions describe what data has done, or are you an insistent extrapolator. The proper way to term it is: the world has warmed during the last century, not the world is warming.
Now would be a good time to link to the various blink comparisons showing the first half of the 20th century before they removed its inconvenient warmth, for Mike’s benefit. Evidently, Karl, Hansen, and others think the greatest generation was too stupid to read a thermometer. Of course, Hansen’s generation never figured it out either as evidenced by the periodic adjustments upward of post-1980 temperatures.
Larry Huldén says:
May 19, 2010 at 9:24 pm
Mike said: ” …. But do notice all the slopes are up. The world is warming.”
But, do notice that all “corrections” also go up. The upgoing temps and CO2 do not correlate.
Not true. All the corrections for the first half of the 20th century were down.
It’s the Karl Urban heat island effect:
http://www.imdb.com/title/tt0419706/
I noted the oddness of two virtually identical plots giving different slopes, but figured, what the hell, that’s close enough for climatology. It’s a good day for them if they manage to get the decimal in the right place.
It they will lie about something so easily refuted what else would they lie about? Certainly not about lost, manipulated temperature data.