Note: See update below, new graph added.
There’s a new paper out by Dr. Edward Long that does some interesting comparisons to NCDC’s raw data (prior to adjustments) that compares rural and urban station data, both raw and adjusted in the CONUS.
The paper is titled Contiguous U.S. Temperature Trends Using NCDC Raw and Adjusted Data for One-Per-State Rural and Urban Station Sets. In it, Dr. Edward Long states:
“The problem would seem to be the methodologies engendered in treatment for a mix of urban and rural locations; that the ‘adjustment’ protocol appears to accent to a warming effect rather than eliminate it. This, if correct, leaves serious doubt for whether the rate of increase in temperature found from the adjusted data is due to natural warming trends or warming because of another reason, such as erroneous consideration of the effects of urban warming.”
Here is the comparison of raw rural and urban data:
And here is the comparison of adjusted rural and urban data:
Note that even adjusted urban data has as much as a 0.2 offset from adjusted rural data.
Dr. Long suggests that NCDC’s adjustments eradicated the difference between rural and urban environments, thus hiding urban heating. The consequence:
“…is a five-fold increase in the rural temperature rate of increase and a slight decrease in the rate of increase of the urban temperature.”
The analysis concludes that NCDC “…has taken liberty to alter the actual rural measured values”.
Thus the adjusted rural values are a systematic increase from the raw values, more and more back into time and a decrease for the more current years. At the same time the urban temperatures were little, or not, adjusted from their raw values. The results is an implication of warming that has not occurred in nature, but indeed has occurred in urban surroundings as people gathered more into cities and cities grew in size and became more industrial in nature. So, in recognizing this aspect, one has to say there has been warming due to man, but it is an urban warming. The temperatures due to nature itself, at least within the Contiguous U. S., have increased at a non-significant rate and do not appear to have any correspondence to the presence or lack of presence of carbon dioxide.
The paper’s summary reads:
Both raw and adjusted data from the NCDC has been examined for a selected Contiguous U. S. set of rural and urban stations, 48 each or one per State. The raw data provides 0.13 and 0.79 oC/century temperature increase for the rural and urban environments. The adjusted data provides 0.64 and 0.77 oC/century respectively. The rates for the raw data appear to correspond to the historical change of rural and urban U. S. populations and indicate warming is due to urban warming. Comparison of the adjusted data for the rural set to that of the raw data shows a systematic treatment that causes the rural adjusted set’s temperature rate of increase to be 5-fold more than that of the raw data. The adjusted urban data set’s and raw urban data set’s rates of temperature increase are the same. This suggests the consequence of the NCDC’s protocol for adjusting the data is to cause historical data to take on the time-line characteristics of urban data. The consequence intended or not, is to report a false rate of temperature increase for the Contiguous U. S.
The full paper may be found here: Contiguous U.S. Temperature Trends Using NCDC Raw and Adjusted Data for One-Per-State Rural and Urban Station Sets (PDF) and is freely available for viewing and distribution.
Dr. Long also recently wrote a column for The American Thinker titled: A Pending American Temperaturegate
As he points out in that column, Joe D’Aleo and I raised similar concerns in: Surface Temperature Records: Policy Driven Deception? (PDF)
UPDATE: A reader asked why divergence started in 1960. Urban growth could be one factor, but given that the paper is about NCDC adjustments, this graph from NOAA is likely germane:
http://www.ncdc.noaa.gov/img/climate/research/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif
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My question is why bother adjusting rural data? Surely there is no need to adjust temperatures that are not influenced by man?
Can’t we have a world, raw, rural dataset only? Mapped over 100 years or so it should show the trend better than the homogonised, urban sprawl contaminated data.
“The divergence problem with the tree ring data is actually non-existent, because the premise is based on comparing it to the “bad” temperature data.”
That, my friend, is an excellent observation. Kudos!
I would guess the divergence starting around 1960 is somewhat related to increased use of air conditioning and reduction in the rooftop gardens in urban environments that started around the same timeframe. It’s not surprising that the concrete jungles have become increasingly warm heat bubbles; night time light pollution has also exploded (just look at the photos from the space shuttle and ISS).
The question is how much effect that has on the enormous energy pool we call climate. The two graphs — if accurate — certainly seem to be prima facie evidence that GISS is cooking the books. I’d love to get Dr. Curry’s reaction to this.
If urban area of the planet is, and I don’t have anything other than a one half second guess, but .01% of the earth’s surface, then to calculate the planet’s temperature, should not the number of urban stations being read be no more than one-ten-thousandth of the number of rural & oceanic sites?
you guys are missing the obvious…
those rural stations are not reflecting the recent warming, therefore they must be adjusted.
Even the text I use to teach high school Earth Science gets the UHI effect correct.
Steveta_uk (00:38:35), very funny; just the kind of understated humor I like.
Mike Bryant (04:56:27) : “Perhaps Judith would care to comment on these developments and similar problems being laid bare all over the world.”
It occurred to me that Dr. Curry could “peer review” this paper. If it’s worthy (perhaps with changes) of publication in a “legit” journal, perhaps she could even help with the process. Obviously she may not have the time/expertise/interest, and this may not be the best topic for outreach to the climate realists, but maybe…
ANTHONY ALERT – ANTHONY ALERT
http://www.foxnews.com/scitech/2010/02/26/climate-data-compromised-by-heat-sources/
Your surfacestation.org is on front page Fox News
but the Redding, Calif and Hopkinsville, Ky station links are broken
Hanksville, Tahoe City and Marysville links do work.
REPLY: They didn’t tell me they were planning to post a story and link to my web page, had I known I could have told them where to link to. So much traffic it should down my office network. I had to turn off the webserver to protect my business. -A
There was a change at NOAA in those tipping poit years:
http://www.lib.noaa.gov/noaainfo/heritage/ReorganizationPlan2.html
Anthony: The slideshow part of the Fox News item is working, however.
You are going to need mirror sites if this keeps up.
REPLY: Working on it now. My main gallery library is on high bandwidth, but my portal page is still on my office network. Setting up structure to move it now.
A
Kasmir (09:51:11) :
My guess is that the divergence starting in 1965 was related to emissions controls beginning to be put in place in the USA.
If you’ll look at the following link you will see that the divergence is related to many factors. However the one most closely approximating the trend above is the TOBS (Time of Observation) adjustment. Second, and occuring earlier, is the switch from the old max/min thermometers. Since both were mostly completed by 1995, can anyone explain to me why the adjusted anomaly keeps going up. Once you’ve adjusted for these “alledged” errors, the anomaly should remain static. If whatever difference TOBS represents, it seems to me that as stations change there will be an uptrend until that change is met. When all stations have been adjusted, then the anomaly should remain static at that temperature addition.
http://wattsupwiththat.com/2009/06/28/an-australian-look-at-ushcn-20th-century-trend-is-largely-if-not-entirely-an-artefact-arising-from-the-%e2%80%9ccorrections%e2%80%9d/
This study caught me in the middle of making station studies:
http://www.robertb.darkhorizons.org/WhatGlobalWarming.htm
Grants Pass, Ore – complete to 1982 with 2008 on the end.
Monster gaps in NCDC B91’s from 1950 to 1979 missing, data cannot be confirmed but is available. Whole months filled in from nearby Ashland, Ore
Sacramento, Ca – from AMS Journals and Un. of Utah data.
Weaverville, Ca – from Un. of Utah, dri.edu purchased set, NCDC B91’s, Trinity Journal Newspaper.
Orleans, Ca – shows spurrious data on back end of set, but it’s still not showing global warming.
What I do see in the rural sets is a step up in the early 20’s, then a slowly shrinking yearly diurnal indicating increasing moisture (from the pre-Dust Bowl dry years to present).
The 3 rural stations completed show flat line from 1920’s to present.
Only Sacramento shows the UHI beginning in 1965, exactly where it should be.
What global warming??
I pick my stations with length in mind, not because I want them to show global cooling, but because I want to see what’s been going on as far back as possible. The West Coast of the US is the gateway to the rest of the nation.
What happens or doesn’t happen out here runs downhill to the rest of you.
Global Warming/Cooling is NOT the burning issue. It’s what changes have occured in the past and may happen again.
The travesty is that the climate institutions of the world can’t seem to deliver a product that is either useful, forecastable, or reasonable.
There is a world of information out there waiting to see the light of day.
The problem is the warming agenda semi jacknifed on the freeway.
Somebody call the bulldozer dept. and order a fleet to clear the rubble.
Hans Erren (03:50:03) :
Warning: People using default excel colours usually have little skill in data processing.
LOL! And all vivid red-hot reds are reserved for the exclusive use by the scientists perched on high horses!
So instead of adjusting the urban data down, they adjust the rural data down?
Doesn’t make any sense.
….unless you are desperate to keep as much warming as possible..
It struck me that the variability of the difference between raw and final temperatures varies randomly quite a lot before ~1960, compared to the smooth progression seen later on. This kind of behavior is usually a sign that something fishy is going on. On this graph http://www.solen.info/solar/cycl4.html of solar cycle 4 you can see times where the dark blue curve looks very smooth vs. other times where it wiggles a lot more. The smooth portions are when there was no data, and Rudolf wolf simply interpolated to fill in the data gaps.
It does strike me that most of the UHI is caused by gas or electric-powered heat, light, aircon or transport activities, plus some heavy breathing by the 5 billion city-dwellers. All of these emit CO2, so it is hardly surprising that the growth if UHI shows a strong correlation with the growth in CO2.
Perhaps we could use CO2 as a proxy for the UHI and adjust the record to remove it, killing two birds with one stone – we get an accurate temperature record and eliminate AGW from the records, all in one go. Can’t be worse than bristlecone pines!
Sorry “growth in UHI effect”
Lubos Motl
I carry historic instrumental records on my site (including Prague)
http://climatereason.com/LittleIceAgeThermometers/
Comparing Prague with even older (but not necessarily continous) records is interesting as this demonstrates the early 18th Century warming that comes prior to Prague being operational-see Berlin Uppsala Stockholm and UK.
The trend for Prague can therefore be seen in even better context if we look back those additional 50 years or so.
It appears likely that the period around 1730 was at least as warm as today.
Tonyb
The last chart posted came from here.
http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html
where they have their own version of what they do to the data and ttheir own chart comparing Raw data with Urban data.
http://www.ncdc.noaa.gov/img/climate/research/ushcn/rawurban3.5_pg.gif
Does anyone miss Robert?
janama (12:00:59) :
That second link, graph yer posted.. what exactly is it showing? raw urban+rural vrs Urban ajusted? Thats how the labeling implies to me? Do they have a raw rural vrs raw urban? Yah know apples n apples.
Intriguing thread, It would be interesting to see a straight comparison with all raw rural vrs all raw urban…. globally:-)
What I’d like to see would be 50 year rural ground temperatures from around the world in areas with little or no measurable geothermal activity.
Leif Svalgaard (11:53:09) :
Yes, filled-in never looks right when it’s strictly interpolated as the shortest distance between two points.
Station data gaps are a huge headache. You want the real deal, but that’s not always the case. A day is a drop in the proverbial bucket. A month is a wound best filled in by a nearby station’s yearly output adjusted to mate with the patterns. A year missing is a 365 car crackup, because you can only adjust the nearby station pattern to sit in between the previous and suceeding years.
There in no guarantee that the missing data filled in by a nearby station is going to behave as the real deal, so the greater the wound, the more serious the scar.
Staking big claims on such premises is a slippery fish on the deck of a boat in rough seas.
“PaulS (05:34:55) :
[…]
The BBC story did talk about the conveyor belt and may cause winters earlier today, however, they have now changed the story, which no longer mentions cold winters, but does talk about the iceberg causing food shortages for pengiuns, which will have to travel much further for food.”
Oh no, they seem to be pretty sure about the danger to the oceanic conveyor belt system, i can read it right now:
“”That means that the bottom water production rate… will decrease.
“The bottom water spills over the continental shelf, flows down the continental slope into the deep ocean.”
This process helps drive the “conveyor belt” of currents in the Southern, Pacific and Atlantic Oceans.
Any disruption to the net flow of bottom water could result in a weakening in the deep ocean circulation system, which plays a key role in the global climate system. ”
Good Old BBC. Never let a good scare story go to waste.
At his blog in the Echo comments to “NCDC UrbanGate: how the urban warming was exported to U.S. countryside,” Motl makes a good point, that it seems hard to cherry-pick 48 sites so that the urban and rural data squiggle so nicely together for decades, then diverge so much, urban rising further and further above rural (while still squiggling alike).
That’s not to say that the study doesn’t need followup and verification. It very much deserves followup for verification.