An Interesting Source of Man-Made Global Warming

The US Historical Climate Network (USHCN) reports about a 0.6C temperature increase in the lower 48 states since about 1940.  There are two steps to reporting these historic temperature numbers.  First, actual measurements are taken.  Second, adjustments are made after the fact by scientists to the data.  Would you like to guess how much of the 0.6C temperature rise is from actual measured temperature increases and how much is due to adjustments of various levels of arbitrariness?  Here it is, for the period from 1940 to present in the US:

Actual Measured Temperature Increase: 0.1C
Adjustments and Fudge Factors: 0.5C
Total Reported Warming: 0.6C

Yes, that is correct.  Nearly all the reported warming in the USHCN data base, which is used for nearly all global warming studies and models, is from human-added fudge factors, guesstimates, and corrections.

I know what you are thinking - this is some weird skeptic's urban legend.  Well, actually it comes right from the NOAA web page which describes how they maintain the USHCN data set.  Below is the key chart from that site showing the sum of all the plug factors and corrections they add to the raw USHCN measurements:
Ushcn_corrections
I hope you can see this significance.  Before we get into whether these measurements are right or wrong or accurate or guesses, it is very useful to understand that almost all the reported warming in the US over the last 70 years is attributable to the plug figures and corrections a few government scientists add to the data in the back room.  It kind of reduces one's confidence, does it not, in the basic conclusion about catastrophic warming? 

Anyway, lets look at the specific adjustments.  The lines in the chart below should add to the overall adjustment line in the chart above.
Ushcn_corrections2

  • Black line is a time of observation adjustment, adding about 0.3C since 1940
  • Light Blue line is a missing data adjustment that does not affect the data much since 1940
  • Red line is an adjustment for measurement technologies, adding about 0.05C since 1940
  • Yellow line is station location quality adjustment, adding about 0.2C since 1940
  • Purple line is an urban heat island adjustment, subtracting about 0.05C since 1950.

Let's take each of these in turn.  The time of observation adjustment is defined as follows:

The Time of Observation Bias (TOB) arises when the 24-hour daily
summary period at a station begins and ends at an hour other than local
midnight. When the summary period ends at an hour other than midnight,
monthly mean temperatures exhibit a systematic bias relative to the
local midnight standard

0.3C seems absurdly high for this adjustment, but I can't prove it.  However, if I understand the problem, a month might be picking up a few extra hours from the next month and losing a few hours to the previous month.  How is a few hour time shift really biasing a 720+ hour month by so large a number? I will look to see if I can find a study digging into this. 

I will skip over the missing data and measurement technology adjustments, since they are small.

The other two adjustments are fascinating.  The yellow line says that siting has improved on USHCN sites such that, since 1900, their locations average 0.2C cooler due to being near more grass and less asphalt today than in 1900. 

During this time, many sites were relocated from city locations to
airports and from roof tops to grassy areas. This often resulted in
cooler readings than were observed at the previous sites.

OK, without a bit of data, does that make a lick of sense?  Siting today in our modern world has GOT to be worse than it was in 1900 or even 1940.  In particular, the very short cable length of the newer MMTS sensors that are standard for USHCN temperature measurement guarantee that readings today are going to be close to buildings and paving.  Now, go to SurfaceStations.org and look at pictures of actual installations, or look at the couple of installations in the Phoenix area I have taken pictures of here.  Do these look more grassy and natural than measurement sites were likely to be in 1900?  Or go to Anthony Watts blog and scroll down his posts on horrible USHCN sites.

The fact is that not only is NOAA getting this correction wrong, but it probably has the SIGN wrong.  The NOAA has never conducted the site by site survey that we discussed above.  Their statement that locations are improving is basically a leap of faith, rather than a fact-based conclusion.  In fact, NOAA scientists who believe that global warming is a problem tend to overlay this bias on the correction process.  Note the quote above -- temperatures that don't increase as they expect are treated as an error to be corrected, rather than a measurement that disputes their hypothesis.

Finally, lets look the urban heat island adjustment.  The NOAA is claiming that the sum total of urban heat island effects on its network since 1900 is just 0.1C, and less than 0.05C since 1940.  We're are talking about the difference between a rural America with horses and dirt roads and a modern urban society with asphalt and air conditioning and cars.  This rediculously small adjustment reflects two biases among anthropogenic global warming advocates:  1)  That urban heat island effects are negligible and 2) That the USHCN network is all rural.  Both are absurd.  Study after study has show urban heat island effects as high as 6-10 degrees.  Just watch you local news if you live in a city --  you will see actual temperatures and forecasts lower by several degrees in the outlying areas than in the center of town.  As to the locations all being rural, you just have to go to surfacestations.org and see where these stations are.  Many of these sites might have been rural in 1940, but they have been engulfed by cities and towns since.

To illustrate both these points, lets take the case of the Tucson site I visited.  In 1900, Tucson was a dusty one-horse town (Arizona was not even a state yet).  In 1940, it was still pretty small.  Today, it is a city of over one million people and the USHCN station is dead in the center of town, located right on an asphalt parking lot.  The adjustment NOAA makes for all these changes?  Less than one degree.  I don't think this is fraud, but it is willful blindness.

So, let's play around with numbers.  Let's say that instead of a 0.2C site quality adjustment we instead used a -0.1C adjustment, which is still probably generous.  Let's assume that instead of a -0.05C urban adjustment we instead used -0.2C.  The resulting total adjustment from 1940 to date would be +0.05 and the total measurement temperature increase in the US would fall from 0.6C to 0.15C.  And this is without even changing the very large time of observation adjustment, and is using some pretty conservative assumptions on my part.  Wow!  This would put US warming more in the range of what satellite data would imply, and would make it virtually negligible. It means that the full amount of reported US warming may well be within the error bars for the measurement network and the correction factors.

While anthropogenic global warming enthusiasts are quick to analyze the reliability of any temperature measurement that shows lower global warming numbers (e.g. satellite), they have historically resisted calls to face up to the poor quality of surface temperature measurement and the arbitrariness of current surface temperature correction factors.  As the NOAA tellingly states:

The U.S. Historical Climatology Network (USHCN, Karl et al. 1990)
is a high-quality moderate sized data set of monthly averaged maximum,
minimum, and mean temperature and total monthly precipitation developed
to assist in the detection of regional climate change. The USHCN is
comprised of 1221 high-quality stations from the U.S. Cooperative
Observing Network within the 48 contiguous United States.

Does it sound defensive to anyone else when they use "high-quality" in both of the first two sentences?  Does anyone think this is high qualityOr this?  Or this?  Its time to better understand what this network as well as its limitations.

My 60-second climate skepticism argument is here.  The much longer paper explaining the breath of skeptic's issues with catastrophic man-made global warming is available for free here.

PS- This analysis focuses only on the US.  However, is there anyone out there who thinks that measurement in China and India and Russia and Africa is less bad?

UpdateThis pdf has an overview of urban heat islands, including this analysis showing the magnitude of the Phoenix nighttime UHI as well as the fact that this UHI has grown substantially over the last 30 years.

Uhi1

Update2: Steve McIntyre looks at temperature adjustments for a couple of California Stations.  In one case he finds a station that has not moves for over one hundred years getting an adjustment that implies a urban heat island reduction over the past 100 years.

  • Josh

    Your summary at the start of the entry quotes in degrees celcius. The labels on the axes of the graphs quote in degrees farenheit. Am i missing something?

  • Malcontent

    OMG you are a genious!!!!

    You have totally convinced me that you have found something not one of the thousands of climatologists have thought of.

    Man you are like wile-e-coyote Suuuuperrrrr Geeeeeeeenious.

    You cracked it!. All those scientists are stupid and corrupt. They only pretend to publish scientific papers but they really just do it for the money. You are incorruptible and smarter then all of them combined.

    Thank you. You have once and for all proved that there is no such thing as global warming.

    It was all fudge factors!!!. Who knew???

    You did!!!!!

  • Rick C

    Malcontent has certainly named himself well. Rather than take issue with the data and the conclusions, he leaps immediately to sarcasm. That is the sign of a pathetic individual.

    He states "It was all fudge factors!!!. Who knew???". Well, most of us knew. Even the bureaucrats at the IPCC have been steadily backing off their predictions.

    I suggest that Malcontent spend more time reading real data and far less time writing sarcasm. It appears he does neither very well at all.

    Rick

  • http://www.lifeofearth.blogspot.com Tarun K Juyal

    I am a regular reader of your article. And I am very impress with your blog upon Global Warming. Now I am also write a blog upon Global Warming. This blog is collection of news & reviews like the study found that global warming since 1985 has been caused neither by an increase in solar radiation nor by a decrease in the flux of galactic cosmic rays. Some researchers had also suggested that the latter might influence global warming because the rays trigger cloud formation.

  • Anon E. Mouse

    Thank you for your insightful analysis, Malcontent.

    Calm, cool logic from a believer in the One True Faith is a refreshing counterpoint to Coyote's incoherent ramblings.

  • CTD

    I have the same question as the first commenter. Is the .6 figure for the total reported warming supposed to be celcius or farenheit? All your points remain valid, but if you convert the .6C to 1.08F and assume the .5 degree "fudge factor" number is also in farenheit, then the guestimations make up 1/2 of the total "warming" rather than 5/6 of it. A bad situation either way, but the latter is MUCH worse than the former.

    I admit I could be dense as well. The NOAA site maddeningly seems to use both English and metric temps in places with no rhyme or reason.

  • T J Sawyer

    Commenters above are correct, Coyote, the text on the NOAA site says "Applying the Time of Observation adjustment (black line) resulted in approximately a 0.3F warming from the late 1960's to the 1990's."

    That is .3F not .3C

  • http://www.lifeofearth.blogspot.com Tarun K Juyal

    I am a regular reader of your article. And I am very impress with your blog upon Global Warming. Now I am also write a blog upon effects and causes of Global Warming. This blog is collection of news & reviews like the study found that global warming since 1985 has been caused neither by an increase in solar radiation nor by a decrease in the flux of galactic cosmic rays. Some researchers had also suggested that the latter might influence global warming because the rays trigger cloud formation.

  • http://www.scottthong.wordpress.com Scott

    Hi Coyote, your postings have been very informative to me. Combining this post on the fudge factors and the STUPIDly placed climate stations, I put it into worded form and mailed it to the local papers.

    No one else seems concerned about global warming here in Malaysia - all we get is the occasional direct-from-Associated-Press report, and always unquestioningly believing.

    Anyways, credit and kudos to you!

    http://scottthong.wordpress.com/2007/08/08/the-sun-fuzzzy-facts-on-the-climate/

  • http://woodedpaths.blogspot.com/ DWPittelli

    The Time of Observation Bias (TOB) is not a mere matter of a month "picking up a few extra hours from the next month and losing a few hours to the previous month."

    Suppose you check and reset your min/max thermometers every day just after the high, say 4:00 PM. On a cold day, a day after a hot day, your high temp reading is apt to come from the previous day at 4:01 PM. That previous day's hot high is effectively double-counted. With 4:00 PM readings this will not happen with a low.

    If instead, you check and reset your min/max thermometers every day near the low, say 6:00 AM, you will never double-count a high high; instead, on a warm night/morning, but a day after a cold morning, you will double-count the previous day's cold low from 6:01 AM.

    In sum, your daily average temperatures (average of high and low) will be lower if you read each morning than if you read each afternoon.

  • http://woodedpaths.blogspot.com/ DWPittelli

    It is unfortunate (and a bit odd) that the NOAA decided to use Fahrenheit for this information and that you did not catch it before "publishing" here. But that still leaves about half of the temperature increase from adjustment factors, something still worth pointing out.

    Exactly how much of an adjustment makes sense for Time-of-day factors is a complex issue, which will vary from site to site as well as season and specific times, and I have no position on the numbers used on that. But the UHI adjustment does seem suspiciously low to me.

  • Nick

    Actual Measured Temperature Increase: 0.1C
    Adjustments and Fudge Factors: 0.5C
    Total Reported Warming: 0.6C

    ----------------

    Where do these figures come from? The graph above shows the adjustment as 0.5 F not C?

    Do you have a total reported warming reference for the US, preferably from NOAA

  • http://www.trygghetsvakten.se Avfuktare Vind

    As shown recently the true error bound of ground based readings is probably exceeding 2°C. Much better to focus on UAH/RSS data from MSU/AMSU (satellites).

  • jerry

    i would like to have the application of nooa data to either environmental monitoring or global warming.

  • Microyank

    I worked at NOAA while much of this work was being done....done through different administrations, some of which downplayed climate change (Reagan, Bush), some of which were sympathetic to the research (Clinton). There was certainly no political agenda by the scientists working on these data, just a desire to try to improve data sets which had many problems and some very poor historical information on instrument sitings etc. There was no "agenda" for proving global climate change....at least not any more than that shared by scientists on the anti-climate change side of the fence.

  • Microyank

    I worked at NOAA while much of this work was being done....done through different administrations, some of which downplayed climate change (Reagan, Bush), some of which were sympathetic to the research (Clinton). There was certainly no political agenda by the scientists working on these data, just a desire to try to improve data sets which had many problems and some very poor historical information on instrument sitings etc. There was no "agenda" for proving global climate change....at least not any more than that shared by scientists on the anti-climate change side of the fence.