By Steve Goddard
As Bob Tisdale pointed out, Tom Karl’s NCDC trend claims don’t match his graph. The trend line is less than either of the claimed V2 or V3 trends in the graph below.
But beyond this blatant error, there are other problems with his graph. Why did it start in 1900? NCDC has data going back to 1880. As you can see below, temperatures dropped from 1880 for about 30 years, which reduces the long term slope considerably.
http://www.ncdc.noaa.gov/img/climate/research/global-jan-dec-error-bar-pg.gif
Now let’s compare his graph vs. Had-Crut, which goes back to 1850. Had-Crut is shown in green, and NCDC V3 is shown in red, at the same scale. Note that there is a huge divergence over the last ten years vs. Had-Crut. The Had-Crut long term trend is 0.45C/century, about half of what Tom Karl is claiming.
It appears that someone is hiding the decline at both ends of the graph.
UPDATE from Steve Goddard:
When I wrote the article I did not recognize that the “global” data presented to the Senate in slide 21 was land only. Thanks to Bob Tisdale for pointing it out. The land only data has diverged from global data over the last decade and explains the discrepancy at the right side of the graph. It does not explain why the slide is marked as “global” or why the land only data set was presented to Congress as “unequivocal” evidence of “global” warming. My apologies to Tom Karl for not recognizing which data set he was presenting to Congress in that particular slide.
Clearer skies (more penetrating sunlight) + end of solar minima + urban heat island effects + poor station citing + manmade adjustments = higher temperature readings
Why does this door keep revolving?
The global averages are used to create false impressions (and clearly NCDC is trying to impress).
A CRU email from Phil Jones to Michael Mann, Malcolm Hughes and others, Mar 11, 2003, stated: “Even with the instrumental record, the early and late 20th century warming periods are only significant locally at between 10-20% of grid boxes.”
A start to an investigation of areas with / without warming using CRU data:
http://www.appinsys.com/GlobalWarming/SeekingWarming.htm
Imagine that!
Oh, another gate for my collection – Thanks!
Anthony: HADCrut is a combined Land Plus Sea Surface Temp dataset. Your comparison should have been the GCHN Version 3 versus CRUTEM, instead if HADCrut, should it not?
REPLY: Not my post, Goddard’s. But I’ll pass on the question -A
Doesn’t matter how it is dressed up, it is still background warming and perfectly natural, the prestidigitator’s are still massaging the figures, same old, same old, it looks massive (it’s worse than we thought!) and the graphs are designed to do just that, scare, startle and confuse.
If the time scale is increased we would find …well not much out of the ordinary.
I think natural warming is good, so does the earth but there may be a shock in store (lets hope not);
http://www.examiner.com/x-32936-Seminole-County-Environmental-News-Examiner~y2010m5d19-Triple-Crown-of-global-cooling-could-pose-serious-threat-to-humanity
It should be obvious that the data are wrong, not the trends. That will be corrected in version 4.
I haven’t compared V2 with V3 yet, but here’s my old V1, V2 comparison for the Illinois USHCN stations.
Anthony: You replied, “Not my post, Goddard’s. But I’ll pass on the question”
Sorry. I didn’t see Steve’s name earlier.
Regards
Ever notice how all the temperature graphs of this scale start somewhere near the lower left and finish somewhere near the upper right no matter how they are sliced and diced?
“NCDC has data going back to 1880”
So how far would we have to go back to see the even bigger trend.
It’s hell coming out of a LIA.
Steve Goddard,
You can find Hadley land temps on their website. Create a graph of that and NCDC land temps for a fair comparison. For version 2, it looks like this: http://i81.photobucket.com/albums/j237/hausfath/Picture384.png
Still hotter than HadCRU, but not as dramatic. They use somewhat different data, however, since NCDC only uses GHCN. Our various reconstructions (mine, Nick Stokes, Chads, Jeff Id/Roman, Tamino) are a lot close to NCDC than Hadley, likely because we also only use GHCN.
It seems to me that you could perhaps ignore older temperature variations as natural, and claim that only the changes that coincide with increases in CO2 should be considered as part of the trend line.
I don’t know what the CO2 increase line looks like – if it started in 1850, then your point holds perfectly, but if it started in, say 1900, then 1900 is not an unreasonable place to start.
Also, 1880-1900 are only warmer in global temps, not NCDC land-only temps. No nefarious motives behind the truncation.
See http://climateknowledge.org/figures/WuGblog_figures/RBRWuG0072_NCDC_march_temp_global_average_2008.gif for example.
The Had-Crut long term trend is 0.45C/century, about half of what Tom Karl is claiming.
The HadCRUT trend is 0.73° C/century according to the notorious alarmist Lucia Lijlegren.
I mean, it’s an odd argument: it’s undisputed that warming has increased faster in the 20th century, right? So extending a graph way back into the mid-1800s and running a trend line through it as though the increase was monotonic would give a totally mistaken impression of the rate of warming. And why would you want to do that?
Oh. Wait.
Never mind.
Oh that’s a simple one… why start at 1900 ? well tell me what would happen to the line of best fit if I started 10,000 years ago ? it would be flat or so close to it that it wouldn’t matter. So why start at 1900 well that’s when we started digging up oil and using it. In reality it’s really should be the last 50 years or so but I doubt you would like those numbers.
a line of best fit that extends way past the period you’re trying to see the underlying treat will be counter productive, please think about it. If we are looking for a tread in the last 50 years what would happen if I made the line of best fit 100 years, then 200 years and then 300 years ?
I don’t believe these guys are actually that stupid not to understand this, which only leaves me with one conclusion.
Re Bob Tisdale’s question –but if that’s the wrong dataset, then why is the agreement so close prior to the last 10 years?
Alan Cheetham says:
May 20, 2010 at 1:53 pm
I have some I checked out from Phil Jones CRU sets here (Scroll down)
http://www.robertb.darkhorizons.org/WhatGlobalWarming.htm
My selection bias is for stations that did not move or moved only a short distance, and anything I could find that had
records going back as far as possible.
Nice site you got there, btw.
I don’t believe these guys are actually that stupid not to understand this, which only leaves me with one conclusion.
And of course, if you’re trying to compare natural variation to anything attributable to humans, you would see we are in a substantial down-trend for temperature. That blip at the end sure stands out like a sore thumb, doesn’t it? Unbelievably scary if you ask me.
http://wattsupwiththat.com/2009/12/12/historical-video-perspective-our-current-unprecedented-global-warming-in-the-context-of-scale/#more-14034
Now if you don’t see what all the fuss is about after THAT, it leaves me with only one conclusion.
Nigel Leck,
Can you get your mind around the possibility that concurrent warming happened to coincide with the industrial revolution? The planet has warmed at essentially the same rate many times in the pre-SUV era.
I am not saying that CO2 didn’t cause the warming. I am saying that is an assumption. Show us the physical evidence confirming that the recent warming was due to the one CO2 molecule out of every 34 that is emitted by mankind.
Otherwise, your assumption is no more valid than this.
Where are the statisticians? Could Bob T. or WIllis E. kindly explain why people are still allowed to draw straight lines through the these data series when the issue of “stationarity” means that it is statistically invalid to do so. Has “stationarity” gone away as an issue? I would appreciate an explanation.
In that last graphic, there seems to be an issue. It is described as “Now let’s compare his graph vs. Had-Crut, which goes back to 1850. Had-Crut is shown in green, and NCDC V3 is shown in red, at the same scale.”
Note the claim of “at the same scale”. Sorry, but a quick visual inspection shows they very obviously and blatantly are NOT at the same scale. The red graph’s -0.5 level is even with the green graph’s -0.6 level. The red graph’s +0.5 level is about across from the green graph’s +0.4 level, but not precisely.
That image is significantly off and needs to be corrected. I suspect the shift would move the entire red graph upward a bit, and might compress it just a touch. I don’t know exactly how that would show in comparison to the green graph, but nonetheless, it ought to be fixed.
We know the increase in CO2 levels are due to human activity due to the carbon isotopes. Please see :-
http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm
Nigel Leck,
Another assumption, in this case assuming that plants will reject CO2 molecules with one extra neutron.
“Down trend” ?? check for yourself… There doesn’t seem to be a down trend to me.
http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt
or at :-
http://discover.itsc.uah.edu/amsutemps/
Smokey: No one say planets reject carbon based on their atomic weight. Please read the link:-
http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm