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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If the whole idea of linear trends is to plot a straight line on a graph of data, that clearly is NOT astraight line function; then why not put a straight line thorugh the past and present Temps, starting at the pre-Cambrian 600 million years ago; then you will see what the true trend really is.
I like Bobs black graph in fig 5. I can believe that that is more like reality; I see absolutely NO point to the red line though it is apaprent even to a fifth grader; that the red line is not a good replacement for the black graph. Why are we paying so many climatologers to come up with measured observational data like Bob’s fig 5, and then we throw it all away by drawing a line with a straight edge. That is the ultimate in fudging data.
But then it seems like the GCMs are even incapable of reconstructing that straight red line from basic Physics; let alone recover the black real data that Gaia uses to figure out where to go next.
George E. Smith says: ” …NZ should dis-associate itself from the silly Avatar like message; before people think, we are all kooks.”
You’re right, but NZ is in the grip of Europe-like political correctness.
>Am I to understand that NIWA actually determines the Temperature of NZ
>from 7; or is it 8 owl box stations.
What NIWA did, was this: They took the 11 most-warming stations, and made it their control set. These are mostly obscure stations. They then took the 7 most prominent stations, located in the main population centres, and adjusted their temperatures (which showed no warming) to conform to the 11 control stations. They then parade the warming as hailing from the 7 prominent stations. Then, as justification for their adjustments, they trot out the 11-station control set and say “See? They’re the same!”. ROTFL
Where can I find GHCN-v3? I must admit, I am a little baffled by what I am seeing in the spatial distribution of adjustments in GHCN-v2: http://blog.qtau.com/2010/05/would-you-like-yours-well-adjusted.html
Pure speculation: Could the craziness on the map (post 1990) be due to the fact that they stopped updating GHCN-v2 adjustments in anticipation of v3? Or, am I doing something wrong?
REPLY: GHCN3 has not been released yet, in fact it has been delayed. Karl’s mention of it in his PPT is the first notice we’ve had of it’s results – Anthony
Thank you, Anthony. I have been trying very hard to figure out what’s going on with those adjustments and I thought I would check. I was afraid that everything I did with GHCN-v2 was useless because the NCDC had “moved on”.